Ramalingam SS, Belani CP, Ruel C, Frankel P, Gitlitz B, Koczywas M, Espinoza-Delgado I, Gandara D.

Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, Georgia, USA. suresh.ramalingam@emory.edu

Abstract

Background: Belinostat (PXD 101) is a novel inhibitor of class I and II histone deacetylases. This class of compounds has demonstrated anticancer activity in malignant mesothelioma. We conducted a phase II study of belinostat in patients with relapsed malignant pleural mesothelioma.

Methods: Patients with advanced mesothelioma, progression with one prior chemotherapy regimen and Eastern Cooperative Oncology Group performance status 0-2 were eligible. Belinostat was administered at 1000 mg/m intravenously over 30 minutes on days 1-5 of every 3 week cycle. The primary end point was response rate. The Simon two-stage design was used. Disease assessments were performed every two cycles.

Results: Thirteen patients were enrolled. Baseline characteristics were: median age of 73 years; Eastern Cooperative Oncology Group performance status 0 (n = 4), 1 (8) and 2 (1). A median of two cycles of therapy were administered. Disease stabilization was seen in two patients. No objective responses were noted and the study did not meet criteria to proceed to the second stage of accrual. Median survival was 5 months with a median progression-free survival of 1 month. Salient toxicities included nausea, emesis, fatigue, and constipation. One patient died as a consequence of cardiac arrhythmia which was deemed ‘possibly’ related to therapy.

Conclusions: Belinostat is not active as monotherapy against recurrent malignant pleural mesothelioma. Evaluation of combination strategies or alternate dosing schedules may be necessary for further development of this novel agent in mesothelioma.

Glossary

therapy

any of the measures taken to treat a disease. Unproven therapy is any therapy that has not been scientifically tested and approved. Use of an unproven therapy instead of standard (proven) therapy is called alternative therapy. Some alternative therapies have dangerous or even life-threatening side effects. For others, the main danger is that a patient may lose the opportunity to benefit from standard therapy. Complementary therapy, on the other hand, refers to therapies used in addition to standard therapy. Some complementary therapies may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient's sense of well-being. The ACS recommends that patients considering use of any alternative or complementary therapy discuss this with their health care team.

regimen

(rej-uh-men) a strict, regulated plan (such as diet, exercise, or other activity) designed to reach certain goals. In cancer treatment, a plan to treat cancer.

oncology

(on-call-o-jee) the branch of medicine concerned with the diagnosis and treatment of cancer.

emesis

(em-eh-sis) vomiting

chemotherapy

(key-mo-THER-uh-pee) treatment with drugs to destroy cancer cells. Chemotherapy is often used with surgery or radiation to treat cancer when the cancer has spread, when it has come back (recurred), or when there is a strong chance that it could recur.

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Kim S, Buchlis G, Fridlender ZG, Sun J, Kapoor V, Cheng G, Haas A, Cheung HK, Zhang X, Corbley M, Kaiser LR, Ling L, Albelda SM.

Thoracic Oncology Research Laboratory, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6160, USA.

Abstract

Locally produced transforming growth factor-beta (TGF-beta) promotes tumor-induced immunosuppression and contributes to resistance to immunotherapy. This article explores the potential for increased efficacy when combining immunotherapies with TGF-beta suppression using the TGF-beta type I receptor kinase inhibitor SM16. Adenovirus expressing IFN-beta (Ad.IFN-beta) was injected intratumorally once in established s.c. AB12 (mesothelioma) and LKR (lung cancer) tumors or intratracheally in a Kras orthotopic lung tumor model. Mice bearing TC1 (lung cancer) tumors were vaccinated with two injections of adenovirus expressing human papillomavirus-E7 (HPV-E7; Ad.E7). SM16 was administered orally in formulated chow. Tumor growth was assessed and cytokine expression and cell populations were measured in tumors and spleens by real-time PCR and flow cytometry. SM16 potentiated the efficacy of both immunotherapies in each of the models and caused changes in the tumor microenvironment. The combination of SM16 and Ad.IFN-beta increased the number of intratumoral leukocytes (including macrophages, natural killer cells, and CD8(+) cells) and increased the percentage of T cells expressing the activation marker CD25. SM16 also augmented the antitumor effects of Ad.E7 in the TC1 flank tumor model. The combination did not increase HPV-E7 tetramer-positive CD8(+) T cells in the spleens but did induce a marked increase in the tumors. Tumors from SM16-treated mice showed increased mRNA and protein for immunostimulatory cytokines and chemokines, as well as endothelial adhesion molecules, suggesting a mechanism for the increased intratumoral leukocyte trafficking. Blockade of the TGF-beta signaling pathway augments the antitumor effects of Ad.IFN-beta immune-activating or Ad.E7 vaccination therapy. The addition of TGF-beta blocking agents in clinical trials of immunotherapies may increase efficacy.

Glossary

therapy

any of the measures taken to treat a disease. Unproven therapy is any therapy that has not been scientifically tested and approved. Use of an unproven therapy instead of standard (proven) therapy is called alternative therapy. Some alternative therapies have dangerous or even life-threatening side effects. For others, the main danger is that a patient may lose the opportunity to benefit from standard therapy. Complementary therapy, on the other hand, refers to therapies used in addition to standard therapy. Some complementary therapies may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient's sense of well-being. The ACS recommends that patients considering use of any alternative or complementary therapy discuss this with their health care team.

oncology

(on-call-o-jee) the branch of medicine concerned with the diagnosis and treatment of cancer.

immunotherapy

(im-mune-no-THER-uh-pee) treatments that promote or support the body's immune system response to a disease such as cancer.

immunosuppression

(im-mune-no-suh-PREH-shun) a state in which the body's immune system does not respond as it should. This condition may be present at birth, or it may be caused by certain infections (such as human immunodeficiency virus or HIV), or by certain cancer therapies, such as cancer-cell killing (cytotoxic) drugs, radiation, and bone marrow transplantation.

flow cytometry

(flow cy-tom-uh-tree) a test of tumor tissue to see how fast the tumor cells are reproducing and whether the tumor cells contain a normal or abnormal amount of DNA. This test is used to help predict how aggressive a cancer is likely to be. (See also ploidy, DNA, S-phase fraction.)

cytokine

(site-o-kyne) a product of cells of the immune system that may stimulate immunity and cause the regression of some cancers.

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

tumor

an abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Kaneko O, Gong L, Zhang J, Hansen JK, Hassan R, Lee B, Ho M.

Laboratory of Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.

Abstract

Ovarian cancer and malignant mesothelioma frequently express both mesothelin and CA125 (also known as MUC16) at high levels on the cell surface. The interaction between mesothelin and CA125 may facilitate the implantation and peritoneal spread of tumors by cell adhesion, whereas the detailed nature of this interaction is still unknown. Here, we used truncated mutagenesis and alanine replacement techniques to identify a binding site on mesothelin for CA125. We examined the molecular interaction by Western blot overlay assays and further quantitatively analyzed by enzyme-linked immunosorbent assay. We also evaluated the binding on cancer cells by flow cytometry. We identified the region (296-359) consisting of 64 amino acids at the N-terminal of cell surface mesothelin as the minimum fragment for complete binding activity to CA125. We found that substitution of tyrosine 318 with an alanine abolished CA125 binding. Replacement of tryptophan 321 and glutamic acid 324 with alanine could partially decrease binding to CA125, whereas mutation of histidine 354 had no effect. These results indicate that a conformation-sensitive structure of the region (296-359) is required and sufficient for the binding of mesothelin to CA125. In addition, we have shown that a single chain monoclonal antibody (SS1) recognizes this CA125-binding domain and blocks the mesothelin-CA125 interaction on cancer cells. The identified CA125-binding domain significantly inhibits cancer cell adhesion and merits evaluation as a new therapeutic agent for preventing or treating peritoneal malignant tumors.

Glossary

mutation

a change; a change in a gene.

flow cytometry

(flow cy-tom-uh-tree) a test of tumor tissue to see how fast the tumor cells are reproducing and whether the tumor cells contain a normal or abnormal amount of DNA. This test is used to help predict how aggressive a cancer is likely to be. (See also ploidy, DNA, S-phase fraction.)

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

antibody

a protein in the blood that defends against foreign agents, such as bacteria. These agents contain certain substances called antigens. Each antibody works against a specific antigen. (See also antigen.)

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

peritoneal

(pair-uh-tuh-nee-al) the serous membrane that lines the cavity of the abdomen. (More on Peritoneal Mesothelioma.)

Akay OM, Ustuner Z, Canturk Z, Mutlu FS, Gulbas Z.

Department of Hematology, Eskisehir Osmangazi University Medical School, 26480, Eskisehir, Turkey, olga.akay@hotmail.com.

Abstract

The goal of this study was laboratory testing for hypercoagulability in patients with solid tumors using rotation thrombelastogram (ROTEM®) and correlate ROTEM® parameters with routine coagulation tests. A total of 78 untreated patients with cancer were included: 28 gastrointestinal system tumors (group 1), 27 respiratory system tumors (group 2), and 23 miscellaneus group of ovarian, renal, nasopharyngeal, mesothelioma, and unknown origin (group 3). Platelet count was significantly increased in group 2 in respect to group 3 (P < 0.05) and fibrinogen level was significantly increased in group 2 in respect to group 1 (P < 0.05). There was no statistically significant difference between subgroups in respect to TEG parameters. Tumor-node-metastasis (TNM) stages of patients was not also associated with either of TEG parameters. Correlation analysis revealed significant correlation between laboratory parameters and ROTEM® parameters. Fibrinogen showed the strongest correlation with MCF (r > 0.7) and CFT in all assays (INTEM, EXTEM, FIBTEM, APTEM). There were also statistically significant correlations between platelet number and other ROTEM® parameters (INTEM-CFT, -MCF, EXTEM-CFT, -MCF, FIBTEM-MCF, APTEM-CFT, -MCF). In conclusions, our data demonstrates thromboelastographic signs of hypercoagulability in patients with solid tumors. ROTEM® is able to identify the contribution of fibrinogen and platelets to clot strength in this patient population.

Keywords: Thrombelastography, Thrombosis, Cancer

Glossary

platelet

a part of the blood that helps it "stick together" (clot) to promote healing after an injury. Chemotherapy can cause a drop in the platelet count--a condition called thrombocytopenia.

oncology

(on-call-o-jee) the branch of medicine concerned with the diagnosis and treatment of cancer.

metastasis

(meh-tas-teh-sis) the spread of cancer cells to distant areas of the body by way of the lymph system or bloodstream.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

tumor

an abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Turcotte RF, Raines RT.

Medical Scientist Training Program and Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI 53706, USA.

Abstract

One of the tightest known protein–protein interactions in biology is that between members of the ribonuclease A superfamily and the ribonuclease inhibitor protein (RI). Some members of this superfamily are able to kill cancer cells, and the ability to evade RI is a major determinant of whether a ribonuclease will be cytotoxic. The archetypal cytotoxic ribonuclease, onconase (ONC), is in late-stage clinical trials for the treatment of malignant mesothelioma. We present here the first measurement of the inhibition of the ribonucleolytic activity of ONC by RI. This inhibition occurs with K_i = 0.15 μM in a solution of low salt concentration.

Keywords: Cancer; Cytotoxin; Enzyme inhibition; Onconase; Ribonuclease; Salt concentration

Abbreviations: RNase A, bovine pancreatic ribonuclease; RI, ribonuclease inhibitor protein; PBS, phosphate-buffered saline; RNase 1, human pancreatic ribonuclease; ONC, onconase

Glossary

cytotoxic

(site-o-tox-ik) toxic to cells; cell-killing.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Stoppoloni D, Cardillo I, Verdina A, Vincenzi B, Menegozzo S, Santini M, Sacchi A, Baldi A, Galati R.

Laboratory D, Department for the Development of Therapeutic Programs, Centro Ricerca Sperimentale, Regina Elena Cancer Institute, Rome, Italy.

Abstract

Background:
The human embryonic lethal abnormal vision (ELAV)-like protein HuR is a messenger RNA (mRNA)-binding protein that controls the stability of certain transcripts, including cyclooxygenase2 (COX-2).

Methods:
To investigate a possible contribution of dysregulation of mRNA stability to the progression of cancer and to COX-2 over expression in mesothelioma, the authors studied expression of COX-2 and HuR in 5 mesothelioma cell lines (MSTO, NCI, Ist-Mes1, Ist-Mes2, and MPP89) and in a group of 29 human mesothelioma specimens that were characterized previously for COX-2 expression.

Results:
All 5 cell lines expressed HuR, whereas COX-2 was not detectable in MSTO or NCI cells. Treatment with cytokines induced a shift in systolic HuR protein levels in MPP89 and Ist-Mes2 cells that was accompanied by an increase in the expression of COX-2 mRNA and protein. In Ist-Mes1 cells, cytokine stimulation did not cause the passage of HuR from nucleus to cytoplasm, and the synthesis of COX-2 did not increase. In tumor tissues, immunohistochemistry revealed a positive, statistically significant correlation between high COX-2 expression and cytoplasmic localization of HuR (P = .016). Moreover, on univariate analysis, overall survival was found to be influenced strongly by cytoplasmic HuR localization (P = .004).

Conclusions:
The current results suggested that HuR plays a role in tumor progression in mesothelioma and that COX-2 may be a target of its activity in neoplastic cells. Together, these observations indicate that strategies aiming toward the modulation of HuR may have a potential clinical benefit in mesothelioma.

Keywords: human embryonic lethal abnormal vision-like protein, cyclooxygenase-2, mesothelioma, prognosis, immunohistochemistry

Glossary

prognosis

(prog-no-sis) a prediction of the course of disease; the outlook for the cure of the patient. For example, women with breast cancer that was detected early and who received prompt treatment have a good prognosis.

nucleus

(new-clee-us) the center of a cell where the DNA is housed and replicated. Studying the size and shape of a cell's nucleus under the microscope can help pathologists distinguish cancer cells from benign cells.

cytokine

(site-o-kyne) a product of cells of the immune system that may stimulate immunity and cause the regression of some cancers.

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

tumor

an abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Okamoto J, Mikami I, Tominaga Y, Kuchenbecker KM, Lin YC, Bravo DT, Clement G, Yagui-Beltran A, Ray MR, Koizumi K, He B, Jablons DM.

Thoracic Oncology Laboratory, Department of Surgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California, USA.

Abstract

Introduction: Heat shock protein 90 (Hsp90) is an abundant molecular chaperone that mediates the maturation and stability of a variety of proteins associated with the promotion of cell growth and survival. Inhibition of Hsp90 function leads to proteasomal degradation of its mis-folded client proteins. Recently, Hsp90 has emerged as being of prime importance to the growth and survival of cancer cells and its inhibitors have already been used in phase I and II clinical trials.

Methods: We investigated how 17-allylamino-17-demethoxygeldanamycin (17-AAG), a small molecule inhibitor of Hsp90, is implicated in human malignant pleural mesothelioma (MM).

Results: We found that 17-AAG led to significant G1 or G2/M cell cycle arrest, inhibition of cell proliferation, and decrease of AKT, AKT1, and survivin expression in all human malignant pleural mesothelioma cell lines examined. We also observed significant apoptosis induction in all MM cell lines treated with 17-AAG. Furthermore, 17-AAG induced apoptosis in freshly cultured primary MM cells and caused signaling changes identical to those in 17-AAG treated MM cell lines.

Conclusion: These results suggest that Hsp90 is strongly associated with the growth and survival of MM and that inhibition of Hsp90 may have therapeutic potential in the treatment of MM.

Glossary

oncology

(on-call-o-jee) the branch of medicine concerned with the diagnosis and treatment of cancer.

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

apoptosis

a type of cell death in which the cell basically commits suicide; scientists believe some types of cancer may originate from an interruption of this programmed cell death, allowing cells to grow out of control.

Pedretti M, Soltermann A, Arni S, Weder W, Neri D, Hillinger S.

Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland.

Abstract

The antibody-mediated targeted delivery of therapeutics to tumor sites is an attractive avenue for combating cancer while sparing normal tissues. Indeed, five derivatives of the human monoclonal antibodies L19 and F16, specific to splice isoforms of fibronectin and tenascin-C, are currently being investigated in clinical trials in patients with malignancies. Until now, a comparative immunohistochemical analysis of these antibodies, which recognize components of the modified extracellular matrix, was missing. Here, we report that the majority of NSCLC and mesothelioma specimens are stained with both antibodies in the stroma, while non-tumoral lung and mesothelium samples rarely exhibit reactivity with either L19 or F16. In our analysis, the anti-tenascin F16 antibody was found to generally exhibit a stronger staining of desmoplastic stroma surrounding tumor. This superior performance was found to be particularly striking in the case of low-grade non-small cell lung cancer.

Keywords: Therapeutic antibodies; Extra-domain B of fibronectin; Extra-domain A1 of tenascin-C; Non-small cell lung cancer; Mesothelioma; Tumor-targeting

Glossary

monoclonal antibodies

antibodies made in the laboratory and designed to target specific substances called antigens. Monoclonal antibodies which have been attached to chemotherapy drugs or radioactive substances are being studied to see if they can seek out antigens unique to cancer cells and deliver these treatments directly to the cancer, thus killing the cancer cells without harming healthy tissue. Monoclonal antibodies are also used in other ways, for example, to help find and classify cancer cells.

grade

The grade of a cancer reflects how abnormal it looks under the microscope. There are several grading systems for cancer, such as the Gleason score for prostate cancer. Each grading system divides cancer into those with the greatest abnormality (poorly differentiated), the least abnormality (well-differentiated), and those in between (moderately differentiated). Grading is done by the pathologist who examines the tissue from the biopsy. It is important because higher grade cancers tend to grow and spread more quickly and have a worse prognosis.

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

antibody

a protein in the blood that defends against foreign agents, such as bacteria. These agents contain certain substances called antigens. Each antibody works against a specific antigen. (See also antigen.)

tumor

an abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

Kindler HL.

Section of Hematology/Oncology, University of Chicago, Chicago, IL 60637, USA. hkindler@medicine.bsd.uchicago.edu

Abstract

Systemic therapy is the only treatment option for the majority of mesothelioma patients, for whom age, co-morbid medical illnesses, non-epithelial histology, and locally advanced disease often preclude surgery. For many years, chemotherapy had a minimal impact on the natural history of this cancer, engendering considerable nihilism. Countless drugs were evaluated, most of which achieved response rates below 20% and median survival of <1 year. Several factors have hampered the evaluation of systemic regimens in patients with mesothelioma. The disease is uncommon, affecting only about 2500 Americans annually. Thus, most clinical trials are small, and randomized studies are challenging to accrue. There is significant heterogeneity within the patient populations of these small trials, for several reasons. Since all of the staging systems for mesothelioma are surgically based, it is almost impossible to accurately determine the stage of a patient who has not been resected. Patients
with very early stage disease may be lumped together with far more advanced patients in the same study. The disease itself is heterogenous, with many different prognostic factors, most notably three pathologic subtypes—epithelial, sarcomatoid, and biphasic—that have different natural histories, and varying responses to treatment. Finally, response assessment is problematic, since pleural-based lesions are difficult to measure accurately and reproducibly. Assessment criteria often vary between trials, making some cross-trial comparisons difficult to interpret. Despite these limitations, in recent years, there has been a surge of optimism regarding systemic treatment of this disease. Several cytotoxic agents have been shown to generate reproducible responses, improve quality of life, or prolong survival in mesothelioma. Drugs with single-agent activity include pemetrexed, raltitrexed, vinorelbine, and vinflunine. The addition of pemetrexed or raltitrexed to cisplatin prolongs survival.
The addition of cisplatin to pemetrexed, raltitrexed, gemcitabine, irinotecan, or vinorelbine improves response rate. The combination of pemetrexed plus cisplatin is considered the benchmark front-line regimen for this disease, based on a phase III trial in 456 patients that yielded a response rate of 41% and a median survival of 12.1 months. Vitamin supplementation with folic acid is essential to decrease toxicity, though recent data suggests that there may be an optimum dose of folic acid that should be administered; higher doses may diminish the effectiveness of pemetrexed. There are also several unresolved questions about the duration and timing of treatment with pemetrexed that are the subject of planned clinical trials. It is essential to recognize that the improvements observed with the pemetrexed/cisplatin combination, though real, are still modest. Other active drugs or drug combinations may be more appropriate for specific individuals, and further research is still needed
to improve upon these results. Since the majority of mesotheliomas in the United States occur in the elderly, non-cisplatin-containing pemetrexed combinations may be more appropriate for some patients. Now that effective agents have been developed for initial treatment, several classical cytotoxic drugs and many novel agents are being evaluated in the second-line setting. These include drugs targeted against the epidermal growth factor, platelet-derived growth factor, vascular endothelial growth factor, src kinase, histone deacetylase, the proteasome, and mesothelin. Given the progress made in recent years, there is reason to believe that more effective treatments will continue to be developed.

Glossary

therapy

any of the measures taken to treat a disease. Unproven therapy is any therapy that has not been scientifically tested and approved. Use of an unproven therapy instead of standard (proven) therapy is called alternative therapy. Some alternative therapies have dangerous or even life-threatening side effects. For others, the main danger is that a patient may lose the opportunity to benefit from standard therapy. Complementary therapy, on the other hand, refers to therapies used in addition to standard therapy. Some complementary therapies may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient's sense of well-being. The ACS recommends that patients considering use of any alternative or complementary therapy discuss this with their health care team.

systemic therapy

treatment that reaches and affects cells throughout the body; for example, chemotherapy.

staging

the process of finding out whether cancer has spread and if so, how far. There is more than one system for staging. The TNM system, described below, is one used often. The TNM system for staging gives three key pieces of information: T refers to the size of the Tumor N describes how far the cancer has spread to nearby Nodes M shows whether the cancer has spread (Metastasized) to other organs of the body Letters or numbers after the T, N, and M give more details about each of these factors. To make this information somewhat clearer, the TNM descriptions can be grouped together into a simpler set of stages, labeled with Roman numerals. In general, the lower the number, the less the cancer has spread. A higher number means a more serious cancer.

regimen

(rej-uh-men) a strict, regulated plan (such as diet, exercise, or other activity) designed to reach certain goals. In cancer treatment, a plan to treat cancer.

platelet

a part of the blood that helps it "stick together" (clot) to promote healing after an injury. Chemotherapy can cause a drop in the platelet count--a condition called thrombocytopenia.

oncology

(on-call-o-jee) the branch of medicine concerned with the diagnosis and treatment of cancer.

cytotoxic

(site-o-tox-ik) toxic to cells; cell-killing.

chemotherapy

(key-mo-THER-uh-pee) treatment with drugs to destroy cancer cells. Chemotherapy is often used with surgery or radiation to treat cancer when the cancer has spread, when it has come back (recurred), or when there is a strong chance that it could recur.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

pemetrexed

chemotheraputic agent that interferes with a crucial process that allows cancer cells to reproduce and spread. Specifically, pemetrexed stops the production of three enzymes that are required to feed the cancer cell. Often used in combination with cisplatin. Marketed under the name ALIMTA. See: Alimta.

Faoro, Leonardo a; Loganathan, Sivakumar a; Westerhoff, Maria b; Modi, Rahul a; Husain, Aliya N. b; Tretiakova, Maria b; Seiwert, Tanguy a; Kindler, Hedy L. a; Vokes, Everett E. a; Salgia, Ravi a

Abstract

Malignant pleural mesothelioma (MPM) is a disease with few therapeutic options. Protein kinase C beta (PKC[beta]) is involved in important cellular functions. Enzastaurin (LY317615.HCl) is a novel inhibitor of PKC in clinical development. MPM cell lines (7) and patient tumor tissues (24) were evaluated for expression of PKC[beta] by immunoblotting and immunohistochemistry, respectively. In-vitro cell growth assays were performed with enzastaurin with or without cisplatin. Cell migration was evaluated with the wound healing assay. Downstream signaling (survival and focal adhesion pathways) was studied by immunoblotting for related molecules in the presence of phorbol ester with or without enzastaurin. Expression for PKC[beta]1 was seen in all cases, with a mean integrated optical density of 152.5 (standard deviation=95.47, n=24), whereas PKC[beta]2 expression was less intense, with a mean integrated optical density of 11.45 (standard deviation=16.27, n=21). There was a trend toward lower overall survival among patients expressing above-median PKC[beta]1 (P=0.064), but not PKC[beta]2. Robust expression of PKC[beta]1 and low expression of PKC[beta]2 were observed in MPM cell lines. Treatment of MPM cell lines with enzastaurin revealed an IC50 of 5 [mu]mol/l, and strong synergism was observed when combined with cisplatin. Wound healing assay revealed that treatment of H2461 cells with enzastaurin reduced migration by 59.2%. Enzastaurin treatment led to disruption of F-actin architecture. Downstream signaling showed reduced phosphorylation of AKT, FAK (focal adhesion kinase), p130Cas, S6 ribosomal protein, and paxillin. PKC[beta]1 was expressed in the majority of MPM samples. Enzastaurin has preclinical activity against MPM, and exhibited synergism with cisplatin. PKC[beta] inhibition in MPM might be able to reduce the invasiveness of MPM by affecting cytoskeletal function.

Glossary

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

tumor

an abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.