Major adverse cardiovascular events associated with VEGF-targeted anticancer tyrosine kinase inhibitors: a real-life study and proposed algorithm for proactive management

BACKGROUND

Vascular endothelial growth factor receptor (VEGFR)-targeted tyrosine kinase inhibitors (TKIs) are widely used in cancer treatment and burdened by cardiovascular toxicity. The majority of data come from clinical trials, thus in selected populations. The aim of our study is to evaluate the cardiotoxicity profile of VEGFR-targeted TKIs and the impact of cardiovascular risk factors in a real-life population.

PATIENTS AND METHODS

In this cohort, population-based study, patients treated with VEGFR-targeted TKIs, bevacizumab and trastuzumab between 2009 and 2014 were analyzed. A multi-source strategy for data retrieval through hospital, pharmaceutical and administrative databases of the Lombardy region, Italy, has been adopted. The primary endpoint was to determine the incidence and type of major adverse cardiovascular events (MACEs) along with their temporal trend. The secondary endpoint was to define the impact of cardiovascular risk factors in the occurrence of MACEs.

RESULTS

A total of 829 patients were treated with VEGFR-targeted TKIs. Eighty-one MACEs occurred in the first year of follow-up [crude cumulative incidence (CCI): 9.79%] mainly consisting of arterial thrombotic events (ATEs, 31 events, CCI: 3.99%), followed by rhythm disorders (22 events, CCI: 2.66%), pulmonary embolisms and heart failures (13 events each, CCI: 1.57%). While the incidence of most MACEs showed a plateau after 6 months, ATEs kept increasing along the year of follow-up. Hypertension and dyslipidemia were associated with an increase in risk of ATEs [relative risk difference (RRD) +209.8% and +156.2%, respectively], while the presence of previous MACEs correlated with a higher risk of all MACEs in multivariate analysis (RRD 151.1%, 95% confidence interval 53.6% to 310.3%, P < 0.001).

CONCLUSIONS

MACEs occur in a clinically significant proportion of patients treated with VEGFR-targeted TKIs, with ATEs being predominant, mainly associated with hypertension and dyslipidemia. A clinical algorithm for effective proactive management of these patients is warranted.

Using activation status of signaling pathways as mechanism-based biomarkers to predict drug sensitivity

Many complex traits, as drug response, are associated with changes in biological pathways rather than being caused by single gene alterations. Here, a predictive framework is presented in which gene expression data are recoded into activity statuses of signal transduction circuits (sub-pathways within signaling pathways that connect receptor proteins to final effector proteins that trigger cell actions). Such activity values are used as features by a prediction algorithm which can efficiently predict a continuous variable such as the IC50 value. The main advantage of this prediction method is that the features selected by the predictor, the signaling circuits, are themselves rich-informative, mechanism-based biomarkers which provide insight into or drug molecular mechanisms of action (MoA).

Novel approaches for targeting kinases: allosteric inhibition, allosteric activation and pseudokinases

Protein kinases are involved in many essential cellular processes and their deregulation can lead to a variety of diseases, including cancer. The pharmaceutical industry has invested heavily in the identification of kinase inhibitors to modulate these disease-promoting pathways, resulting in several successful drugs. However, the field is challenging as it is difficult to identify novel selective inhibitors with good pharmacokinetic/pharmacodynamic properties. In addition, resistance to kinase inhibitor treatment frequently arises. The identification of non-ATP site targeting ('allosteric') inhibitors, the identification of kinase activators and the expansion of kinase target space to include the less studied members of the family, including atypical- and pseudo-kinases, are potential avenues to overcome these challenges. In this perspective, the opportunities and challenges of following these approaches and others will be discussed.

NOD-scidIl2rg (tm1Wjl) and NOD-Rag1 (null) Il2rg (tm1Wjl) : a model for stromal cell-tumor cell interaction for human colon cancer

BACKGROUND/AIMS

Stromal cells and the extracellular environment are vital to human tumors, influencing growth and response to therapy. Human tumor cell lines lack stroma and transplantation into immunodeficient mice does not allow meaningful analyses of the effects of stroma on tumor cell growth. Studies of xenografts of primary human tumor fragments in nude mice and in early scid mouse models were constrained by poor tumor growth accompanied by host-versus-graft reactivity, dramatically altering tumor architecture and tumor microenvironment. In contrast, severely immunodeficient NOD-scid and NOD-Rag1 (null) strains carrying the IL2rg (null) mutation (NSG and NRG) support the growth of many types of human primary tumors.

METHODS/RESULTS

We compared the take rate, growth and architectural preservation of 10 clinically distinct primary human colon cancers in NOD-scid, NOD-Rag1 (null) , NSG and NRG mice and determined the contribution of mouse and human cells to the stroma during tumor proliferation and expansion in secondary hosts and tumor response to treatment with 5-fluorouracil (5-FU). NSG and NRG mice more readily support growth of human primary colon tumor fragments than do NOD-scid, NOD-Rag1 (null) mice and maintain tumor architectural integrity in the primary recipient and through subsequent transplant generations. The human colon tumors were responsive to treatment with 5-FU. Human stromal cells in the primary graft were replaced by mouse-derived fibroblasts in a dynamic process during subsequent passages.

CONCLUSION

Human colon cancer xenografts propagated in NSG and NRG mice maintain structural fidelity while replacing human stromal cells with murine stromal cells.

Managing immunity in resistant cancer patients correlates to survival: results and discussion of a pilot study

Many cancer patients do not die due to impaired organ functions, but as a result of reduced general conditions, such as cachexia, sarcopenia, depression, infections, or stress. Reduced general health may be caused by immune modifying cytokines released from the tumor into the body. Improvement of immunity would not only reduce cancer side effects through inhibiting cytokine release from the tumor into the blood, but also, according to a new hypothesis, modify the cancer stem cells (CSC) in the tumor, which are believed to drive cancer growth and metastasis. We reported previously several investigations with a dietary fermented soy formulation (FSWW08) in cancer patients, where we saw a) strong reduction of cancer symptoms, b) broken resistance to chemotherapy, and c) a strong reduction of chemotherapy's toxic side effects, when taken in combination. This publication reports two new findings from a pilot study with postsurgical, treatment resistant patients conducted over four years. First, neither treatment resistance nor side effects were observed. Second, more patients have survived than expected. The improved health and immunity is detected together with increased CSC differentiation, suggesting lower aggressiveness, which was corroborated by increased gene expressions, particularly of steroidal hormones, MAPkinase, NF-κB, and tumor suppressor factor p53, a typical marker of "stemness" or cell differentiation. Although limited by its small, homogenous sample size, the results of this pilot study illustrate the relationship between CSCs differentiation, and the clinical symptoms of immunity, which influence survival outcomes and raise the clinical potential of measuring CSCs in ovarian, prostate, and breast cancers. The improved survival rates are also seen in larger cohort studies, which show similar gene expression profiles, which were induced by FSWW08 in the treatment resistant cancer patients in this study.

Glioblastoma multiforme

Patients with newly diagnosed glioblastoma multiforme should undergo a maximal tumor resection and then, whenever possible, should be entered into a clinical trial. The current standard of care consists of external beam irradiation, to a total of 60 Gy over 6 weeks, in combination with low-dose daily temozolomide, followed by at least six cycles of adjuvant temozolomide. If radiotherapy and a temozolomide-based adjuvant regimen fail, the most active treatment approach appears to be bevacizumab and irinotecan. Molecular therapy, with drugs targeting growth factor receptors and critical signal transduction pathway mediators, is also under active investigation.

Modification of cysteine 179 of IkappaBalpha kinase by nimbolide leads to down-regulation of NF-kappaB-regulated cell survival and proliferative proteins and sensitization of tumor cells to chemotherapeutic agents

Reverse pharmacology, also called the "bedside to bench" approach, that deals with new uses for a well known molecular entity has been used extensively in cancer drug development to identify novel compounds and delineate their mechanisms of action. Here, we show that nimbolide, a triterpenoid isolated from Azadirachta indica, enhanced the apoptosis induced by inflammatory cytokines and chemotherapeutic agents in tumor cells. This limonoid abrogated the expression of proteins associated with cell survival (Bcl-2, Bcl-xL, IAP-1, and IAP-2), proliferation (cyclin D1), invasion (MMP-9), and angiogenesis (VEGF), all regulated by nuclear factor (NF)-κB. Nimbolide inhibited the activation of NF-κB induced by carcinogens and inflammatory stimuli. Constitutively active NF-κB found in most tumor cells was also inhibited. We found that suppression of NF-κB activation by nimbolide was caused by inhibition of IκB kinase (IKK), which led to suppression of IκBα phosphorylation and degradation, nuclear translocation, DNA binding, and gene transcription. Reducing agent reversed the action of the limonoid, suggesting the involvement of a cysteine residue. Replacement of Cys(179) of IKK-β with alanine abolished the effect of nimbolide, suggesting that Cys(179) plays a critical role in inhibiting the NF-κB activation. Overall, our results indicate that nimbolide can sensitize tumor cells to chemotherapeutic agents through interaction with IKK, leading to inhibition of NF-κB-regulated proteins.

Synthesis and antitumor activity of novel 2',3'-diethanethio-2',3',5'-trideoxy-5'-triazolonucleoside analogues

A series of novel 2',3'-diethanethio-2',3',5'-trideoxy-5'-triazoloribonucleosides was synthesized in excellent yields and their antitumor activity was evaluated. These nucleoside analogues with aromatic substituted triazole rings showed significantly improved activity towards a broad range of tumor cell lines and those without arene substitutes were inactive.

ApoG2 induces cell cycle arrest of nasopharyngeal carcinoma cells by suppressing the c-Myc signaling pathway

BACKGROUND

apogossypolone (ApoG2) is a novel derivate of gossypol. We previously have reported that ApoG2 is a promising compound that kills nasopharyngeal carcinoma (NPC) cells by inhibiting the antiapoptotic function of Bcl-2 proteins. However, some researchers demonstrate that the antiproliferative effect of gossypol on breast cancer cells is mediated by induction of cell cycle arrest. So this study was aimed to investigate the effect of ApoG2 on cell cycle proliferation in NPC cells.

RESULTS

We found that ApoG2 significantly suppressed the expression of c-Myc in NPC cells and induced arrest at the DNA synthesis (S) phase in a large percentage of NPC cells. Immunoblot analysis showed that expression of c-Myc protein was significantly downregulated by ApoG2 and that the expression of c-Myc's downstream molecules cyclin D1 and cyclin E were inhibited whereas p21 was induced. To further identify the cause-effect relationship between the suppression of c-Myc signaling pathway and induction of cell cycle arrest, the expression of c-Myc was interfered by siRNA. The results of cell cycle analysis showed that the downregulation of c-Myc signaling pathway by siRNA interference could cause a significant arrest of NPC cell at S phase of the cell cycle. In CNE-2 xenografts, ApoG2 significantly downregulated the expression of c-Myc and suppressed tumor growth in vivo.

CONCLUSION

Our findings indicated that ApoG2 could potently disturb the proliferation of NPC cells by suppressing c-Myc signaling pathway. This data suggested that the inhibitory effect of ApoG2 on NPC cell cycle proliferation might contribute to its use in anticancer therapy.

Systemic therapy for unresectable and metastatic transitional cell carcinoma of the urothelium: first-line and beyond

PURPOSE OF REVIEW

The review aims to provide an overview of recent advances and future research direction in the management of patients with advanced transitional cell carcinoma.

RECENT FINDINGS

Early data of the randomized phase III study comparing paclitaxel, cisplatin, and gemcitabine with gemcitabine plus cisplatin for advanced urothelial cancer detected no survival difference. A phase II study investigated the safety and efficacy of trastuzumab, carboplatin, gemcitabine, and paclitaxel in human epidermal growth factor receptor-2/neu-positive advanced urothelial carcinoma and reported promising results. Renal-sparing regimens are under active development. A nonrandomized comparison of the 3-week with the 4-week schedule for gemcitabine and cisplatin showed that the 3-week schedule had less hematological toxicity and better dose intensity. Potential molecular markers such as excision repair cross-complementation group 1, emmprin, and survivin for survival and/or platinum resistance in patients with transitional cell carcinoma showed promise.

SUMMARY

Recent data do not support change in the current standard of care for advanced transitional cell carcinoma. Clinical testing of emerging anticancer therapies using new agents, new combinations, and new approaches is under active investigation. Rational combination and new strategy in clinical trial design are critical for new drug development for transitional cell carcinoma.

Knowledgebase for addiction-related genes: is it possible an extrapolation to rational multi-target drug design?

In recent years the single-probe-single-target approach in drug design has started to be smoothly replaced by the single-probe-multiple-target (or multi-target) one, where a single drug is able to tackle different, but disease-related targets in a selective manner. However, the design of multi-target drugs has been hindered by a lack of a systematic network of disease-related common pathways. The recent development of the knowledgebase of addiction-related genes (KARG) has provided important hints on how to rationally design multi-target probes by connecting experimental techniques with available network models. In this perspective, the use of KARG as a template to build knowledgebases of disease-related genes for the rational multi-target drug design is suggested. Moreover, it is proposed that building knowledgebases of disease-related genes will become a necessary and ubiquitous tool in the rational design of multi-target drugs.

Developing and applying a gene functional association network for anti-angiogenic kinase inhibitor activity assessment in an angiogenesis co-culture model

Background

Tumor angiogenesis is a highly regulated process involving intercellular communication as well as the interactions of multiple downstream signal transduction pathways. Disrupting one or even a few angiogenesis pathways is often insufficient to achieve sustained therapeutic benefits due to the complexity of angiogenesis. Targeting multiple angiogenic pathways has been increasingly recognized as a viable strategy. However, translation of the polypharmacology of a given compound to its antiangiogenic efficacy remains a major technical challenge. Developing a global functional association network among angiogenesis-related genes is much needed to facilitate holistic understanding of angiogenesis and to aid the development of more effective anti-angiogenesis therapeutics.

Results

We constructed a comprehensive gene functional association network or interactome by transcript profiling an in vitro angiogenesis model, in which human umbilical vein endothelial cells (HUVECs) formed capillary structures when co-cultured with normal human dermal fibroblasts (NHDFs). HUVEC competence and NHDF supportiveness of cord formation were found to be highly cell-passage dependent. An enrichment test of Biological Processes (BP) of differentially expressed genes (DEG) revealed that angiogenesis related BP categories significantly changed with cell passages. Built upon 2012 DEGs identified from two microarray studies, the resulting interactome captured 17226 functional gene associations and displayed characteristics of a scale-free network. The interactome includes the involvement of oncogenes and tumor suppressor genes in angiogenesis. We developed a network walking algorithm to extract connectivity information from the interactome and applied it to simulate the level of network perturbation by three multi-targeted anti-angiogenic kinase inhibitors. Simulated network perturbation correlated with observed anti-angiogenesis activity in a cord formation bioassay.

Conclusion

We established a comprehensive gene functional association network to model in vitro angiogenesis regulation. The present study provided a proof-of-concept pilot of applying network perturbation analysis to drug phenotypic activity assessment.