Hepatocellular carcinoma: Where there is unmet need

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor most commonly associated with underlying chronic liver disease, especially hepatitis. It is a growing problem in the United States and worldwide. There are two potential ways to prevent HCC. Primary prevention which is based on vaccination or secondary prevention involving agents that slow down carcinogenesis. Several pathways have been thought to play a role in the development of HCC; specifically, those involving vascular endothelial growth factor (VEGF)‐mediated angiogenesis, WNT, phosphatidylinositol 3‐kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR), AMP‐activated protein kinase (AMPK), and c‐MET. Currently, there are only a limited number of drugs which have been proven as effective treatment options for HCC and several clinical trials are testing drugs which target aberrations in the pathways mentioned above. In this review, we discuss currently approved therapies, monotherapies and combination therapy for the treatment of HCC.     

Papel de los nuevos agentes inmunosupresores en el cáncer cutáneo no melanoma en pacientes trasplantados renales

IntroductionNonmelanoma skin cancer (NMSC) is the most common malignancy in patients who have received a solid organ transplant. Multiple factors are involved in the onset of posttransplant NMSC.ObjectivesTo analyze the relationship between new immunosuppressive drugs and the onset of NMSC in renal transplant recipients.MethodThis was a combined retrospective and prospective observational study in which we studied 289 patients who received a kidney transplant between January 1996 and December 2010 at Hospital Universitario Doctor Peset in Valencia, Spain.ResultsSeventy-three patients (25.2%) developed 162 NMSCs over a median follow-up of 72 months. There were no statistically significant differences in the onset of NMSC on comparing different induction therapy strategies involving monoclonal and polyclonal antibodies. NMSCs occurred less frequently in patients treated with mammalian target of rapamycin (mTOR) inhibitors than in those treated with other immunosuppressive regimens, although the differences were not statistically significant. Three of 5 patients with recurrent NMSC who were switched from calcineurin inhibitors to mTOR inhibitors developed additional NMSCs despite the change.ConclusionsInduction therapy with monoclonal and polyclonal antibodies in renal transplant recipients is not associated with an increased risk of NMSC. While mTOR inhibitors are associated with a lower risk of posttransplant NMSC, it remains to be determined whether a switch to these drugs is useful in the management of patients who develop multiple NMSCs.     

静脉麻醉药对脂多糖诱导的神经星形胶质细胞增殖的影响及其机制

目的 检测静脉麻醉药对脂多糖诱导的神经星形胶质细胞的影响及其机制。 方法 利用MTT实验、集落形成实验和Annexin V-FITC/PI双染色法检测静脉麻醉药对脂多糖作用后的神经星形胶质细胞增殖和凋亡的影响。Western blotting技术检测相关机制。 结果 静脉麻醉药可以逆转脂多糖诱导的神经星形胶质细胞增殖。经麻醉药处理后的神经星形胶质细胞p-Akt和p-mTOR蛋白表达下降，Caspase-3和Caspase-9表达水平升高。结论 静脉麻醉药可以通过抑制mTOR通路逆转脂多糖诱导的神经星形胶质细胞增殖。     

FK228 augmented temozolomide sensitivity in human glioma cells by blocking PI3K/AKT/mTOR signal pathways

Temozolomide is a novel cytotoxic agent currently used as first-line chemotherapy for glioblastoma multiforme (GBM). Romidepsin (FK228), a histone deacetylase inhibitor, is a promising new class of antineoplastic agent with the capacity to induce growth arrest and/or apoptosis of cancer cells. However, combination of the two drugs in glioma remains largely unknown. In the present study, we evaluated the combinatory effects of FK228 with TMZ in glioma, and its molecular mechanisms responsible for these effects. Glioma cell lines were treated with TMZ, FK228 or the combination of drugs. The resistance effect including cytotoxicity and apoptosis was determined in glioma cells, respectively. We further evaluated the effects of FK228 in the PI3K/Akt-signaling pathway in vitro. Mice engrafted with 5 × 10⁶ LN382 cells were treated with TMZ, FK228 or the combination of two drugs, and tumor weights and volumes were measured, respectively. FK228 enhanced the cytotoxic effects of TMZ in glioma cells compared to vehicle-treated controls or each drug alone. The combination of FK228 and TMZ-induced apoptosis was demonstrated by increased expression of cleaved-Caspase 3, Bax, cleaved-PARP, and decreased Bcl-2 expression. Furthermore, the expression of key components of the PI3K/Akt-signaling pathway showed that combination of FK228 and TMZ block PI3K/Akt pathways in vitro. This block effect was also confirmed in vivo in mice models. Mice treated with both FK228 and TMZ drugs showed significantly reduced tumor weights and volumes, compared to each drug alone. Our results suggested that FK228 augmented temozolomide sensitivity in human glioma cells partially by blocking PI3K/AKT/mTOR signal pathways. It thus may provide a promising target for improving the therapeutic outcome of TMZ-resistant gliomas, although further studies will be needed.     

Metastatic chromophobe renal cell carcinoma treated with targeted therapies: A Renal Cross Channel Group study

BackgroundTreatment of non–clear cell renal cell carcinoma (RCC) remains controversial despite several recent prospective studies of targeted therapies (TT). Often Vascular Endothelial growth Factor (VEGF) and Mammalian Target of Rapamycin (mTOR) inhibitors are used, extrapolating the data from use of these agents in clear cell RCC.MethodsWe performed a retrospective data analysis within the Renal Cross Channel Group to determine metastatic chromophobe RCC (mChRCC) outcomes in the TT era. The end-points were overall response, overall survival (OS) and time to treatment failure (TTF). The two latter were estimated using the Kaplan–Meier method.Results91 mChRCC patients from 26 centres were included. Median follow-up from the date of first metastasis was 6.1 years (range: 0–13.9). Median OS was 37.9 months (95% confidence interval [CI]: 21.4–46.8) from the diagnosis of metastatic disease. Among the 61 patients who received TT, 50 (82%) were treated with anti-angiogenic (AA) and 11 with mTOR inhibitors. Median TTF and OS in patients receiving a first line of AA was 8.7 months (95% CI: 5.2–10.9) and 22.9 months (95% CI: 17.8–49.2) versus 1.9 months (95% CI: 1.0–6.0) and 3.2 months (95% CI: 2.3–not evaluable) with mTOR inhibitors, respectively. A stratified log-rank test was used to compare AA and mTOR inhibitors TT, while controlling the effect of the International Metastatic RCC Database Consortium risk group and no significant difference between AA and mTOR inhibitors was observed for TTF (p = 0.26) or for OS (p = 0.55).ConclusionWe report the largest retrospective cohort of patients with mChRCC treated with TT and no significant difference between AA and mTOR inhibitors was observed for TTF and OS.     

Second-line systemic therapy for the treatment of metastatic renal cell cancer

The discovery of molecular mechanisms driving the progression of renal cell carcinoma (RCC) has led to the development of drugs that target RCC at the molecular level. Inhibition of VEGF-targeting pathways is successful as a front-line treatment in patients with metastatic RCC. In addition, bevacizumab/IFN-α, sunitinib and pazopanib are recommended for first-line use in good- or intermediate-risk patients, whereas temsirolimus is approved for poor-risk patients. Second-line options are valuable as these patients eventually progress. The present review addresses which drug is best in this second-line setting. Options for sequential therapy include tyrosine kinase inhibitor (TKI)–mTOR inhibitor or TKI–TKI sequences. We also address the question of whether sequential therapy with TKIs or the combination of VEGF followed by mTOR inhibition is the best choice for specific patients, and which sequence of TKIs is most beneficial.     

Toxicity spectrum of inhibitors of mammalian target of rapamycin in organ transplantation: etiology,pathogenesis and treatment

Introduction: Control of the immune responses is critical for body homeostasis. Immunosuppressive strategies have been critical to this enterprise as they reveal molecular and cellular mechanisms of immune-mediated tissue destruction.

Areas covered: While exerting potent effects to blockade critical processes during cell maturation prior to division and effector functions, the novel drug class of mammalian target of rapamycin inhibitors (mTORi) consequently exert adverse reactions due to disruption of pleiotropic physiologic pathways. This review includes selected clinical and preclinical materials from the time of the author's own first-in-human experience in 1993 through to 2009. The goal of this contribution is to provide a foundation in basic biochemical processes to allow the reader to understand the pathophysiology of adverse clinical reactions.

Expert opinion: mTORi, as potent agents for clinical immunosuppression, inevitably, disrupt multiple cellular pathways as well as important vectors of host resistance. Judicious use of this pharmacologic class demands dedication to learning strategies of individualization for patient needs and reactions in the manner of clinicians previously committed on the introduction of calcineurin inhibitors 3 decades ago.