Identification of signature genes associated with therapeutic resistance to anti-VEGF therapy

The Role of Selected Adipocytokines in Ovarian Cancer and Endometrial Cancer

Due to their multidirectional influence, adipocytokines are currently the subject of numerous intensive studies. Significant impact applies to many processes, both physiological and pathological. Moreover, the role of adipocytokines in carcinogenesis seems particularly interesting and not fully understood. For this reason, ongoing research focuses on the role of these compounds in the network of interactions in the tumor microenvironment. Particular attention should be drawn to cancers that remain challenging for modern gynecological oncology-ovarian and endometrial cancer. This paper presents the role of selected adipocytokines, including leptin, adiponectin, visfatin, resistin, apelin, chemerin, omentin and vaspin in cancer, with a particular focus on ovarian and endometrial cancer, and their potential clinical relevance.

Apelin-driven endothelial cell migration sustains intestinal progenitor cells and tumor growth

Stem and progenitor cells residing in the intestinal crypts drive the majority of colorectal cancers (CRCs), yet vascular contribution to this niche remains largely unexplored. VEGFA is a key driver of physiological and tumor angiogenesis. Accordingly, current anti-angiogenic cancer therapies target the VEGFA pathway. Here we report that in CRC expansion of the stem/progenitor pool in intestinal crypts requires VEGFA-independent growth and remodeling of blood vessels. Epithelial transformation induced expression of the endothelial peptide apelin, directs migration of distant venous endothelial cells towards progenitor niche vessels ensuring optimal perfusion. In the absence of apelin, loss of injury-inducible PROX1+ epithelial progenitors inhibited both incipient and advanced intestinal tumor growth. Our results establish fundamental principles for the reciprocal communication between vasculature and the intestinal progenitor niche and provide a mechanism for resistance to VEGFA-targeting drugs in CRCs.

Favorable Prognostic Impact of Cathepsin H (CTSH) High Expression in Thyroid Carcinoma

Background

Presently, no study reported the function of cathepsin H (CTSH) in thyroid carcinoma (THCA). The aim of present study was to initially explore the factors affecting CTSH expression, and association between CTSH expression and survival rate in THCA.

Methods

We explored mRNA expression of CTSH in normal and BRCA tissues, and evaluated prognostic impact of CTSH expression on the overall survival of THCA patients. Then, related factors influencing CTSH mRNA expression in THCA were analyzed. Functional enrichment analysis was performed to reveal the potential function of CTSH involved in THCA. We also constructed PPI network among co-expressed genes of CTSH to determine hub genes, followed by association analysis on hub genes with CTSH.

Results

(1) CTSH mRNA was highly expressed in THCA compared with normal group (P<0.001). High expression of CTSH was conducive to the overall survival of THCA patients (P=0.0027). CTSH was then determined as an independent prognostic factor in THCA (P=0.024). (2) The mRNA expression of CTSH was statistically related to patient’s histological type, N stage, T stage, tumor stage and sample type (all P<0.001). CTSH copy number variation and methylation also influenced its mRNA expression (all P<0.001). (3) Pathway analysis indicated that CTSH mainly participated in cancer-related pathways, such as hedgehog signaling pathway, cytokine–cytokine receptor interaction and JAK-STAT signaling pathway (all P<0.05). (4) The top 10 co-expressed genes in whole PPI network showed significant correlation with CTSH expression (all P<0.001).

Conclusion

CTSH higher expression was observed in THCA, which caused a good prognosis of patients. CTSH expression might be regulated by multiple factors including clinical characteristic, methylation, copy number and other genes. This study demonstrated the clinical significance of CTSH in THCA, as well as revealed the potential pathway associated with CTSH involved in thyroid cancer.

The role of Notch ligand, Delta-like ligand 4 (DLL4), in cancer angiogenesis—implications for therapy

Background

It is generally accepted that angiogenesis is a complex and tightly regulated process characterized by the growth of blood vessels from existing vasculature. Activation of the Notch signalling pathway affects multiple aspects of vascular development. One of the components of the Notch signalling pathway, Delta-like ligand 4 (DLL4), has recently appeared as a critical regulator of tumour angiogenesis and thus as a promising therapeutic target.

Methods

This review article includes available data from peer-reviewed publications associated with the role of DLL4 in cancer angiogenesis. Searches were performed in PubMed, EMBASE, Google Scholar and Web of Science using the terms “tumour angiogenesis”, “DLL4”, “Notch signalling” and “anti-cancer therapy”.

Results

The survival curves of cancer patients revealed that the patients with high DLL4 expression levels had significantly shorter survival times than the patients with low DLL4 expression. Moreover, a positive correlation was also identified between DLL4 and VEGF receptorsʼ expression levels. It seems that inhibition of DLL4 may exert potent growth inhibitory effects on some tumours resistant to anti-VEGF therapies. A great number of blocking agents of DLL4/Notch signalling including anti-DLL4 antibodies, DNA vaccination, Notch antibodies and gamma-secretase inhibitors have been studied in preclinical tumour models.

Conclusion

DLL4 seems to be a promising target in anti-cancer therapy. Nevertheless, the careful evaluation of adverse effects on normal physiological processes in relation to therapeutic doses of anti-DLL4 drugs will be significant for advancement of DLL4 blocking agents in clinical oncology.

Human endoglin-CD3 bispecific T cell engager antibody induces anti-tumor effect in vivo

Rationale: Endoglin, also known as CD105, is a homo-dimeric membrane glycoprotein required for angiogenesis and serves as a marker for cancer vasculature. In this study, we constructed a bispecific T-cell engager (BiTE) antibody that targets human endoglin and CD3 (hEND-CD3/BiTE). We examined BiTE binding to endoglin-expressing cells and its effects on the cytolytic activity of T cells and cancer development.

Methods: The in vitro effects of hEND-CD3/BiTE, including binding to target cells, T-cell activation, proliferation, and cytotoxicity, were examined in endoglin-expressing 293T cells, human umbilical vascular endothelial cells, tumor-derived endothelial cells, and CD3⁺ T cells. An in vivo xenograft tumor model was established using A549 human lung cancer cells. The therapeutic efficacy of hEND-CD3/BiTE was assessed by monitoring tumor growth, angiogenesis, and mouse survival.

Results: hEND-CD3/BiTE specifically bound to endoglin-expressing cells and CD3⁺ T cells in vitro and stimulated T-cell activation, proliferation, and Th1 cytokine secretion, and promoted T-cell-mediated cytolysis of endoglin-expressing cells. The hEND-CD3/BiTE in vivo caused minimal toxicity to major organs, reduced tumor neoangiogenesis, inhibited tumor growth, and significantly improved mouse survival.

Conclusions: Our study demonstrated the therapeutic potential of hEND-CD3/BiTE and provided a novel approach to clinical cancer treatment.

Overcoming Resistance to Tumor-Targeted and Immune-Targeted Therapies

Resistance to anticancer therapies includes primary resistance, usually related to lack of target dependency or presence of additional targets, and secondary resistance, mostly driven by adaptation of the cancer cell to the selection pressure of treatment. Resistance to targeted therapy is frequently acquired, driven by on-target, bypass alterations, or cellular plasticity. Resistance to immunotherapy is often primary, orchestrated by sophisticated tumor-host-microenvironment interactions, but could also occur after initial efficacy, mostly when only partial responses are obtained. Here, we provide an overview of resistance to tumor and immune-targeted therapies and discuss challenges of overcoming resistance, and current and future directions of development. SIGNIFICANCE: A better and earlier identification of cancer-resistance mechanisms could avoid the use of ineffective drugs in patients not responding to therapy and provide the rationale for the administration of personalized drug associations. A clear description of the molecular interplayers is a prerequisite to the development of novel and dedicated anticancer drugs. Finally, the implementation of such cancer molecular and immunologic explorations in prospective clinical trials could de-risk the demonstration of more effective anticancer strategies in randomized registration trials, and bring us closer to the promise of cure.

Identification of Hub Genes and Key Pathways Associated with Anti-VEGF Resistant Glioblastoma Using Gene Expression Data Analysis

Anti-VEGF therapy is considered to be a useful therapeutic approach in many tumors, but the low efficacy and drug resistance limit its therapeutic potential and promote tumor growth through alternative mechanisms. We reanalyzed the gene expression data of xenografts of tumors of bevacizumab-resistant glioblastoma multiforme (GBM) patients, using bioinformatics tools, to understand the molecular mechanisms of this resistance. An analysis of the gene set data from three generations of xenografts, identified as 646, 873 and 1220, differentially expressed genes (DEGs) in the first, fourth and ninth generations, respectively, of the anti-VEGF-resistant GBM cells. Gene Ontology (GO) and pathway enrichment analyses demonstrated that the DEGs were significantly enriched in biological processes such as angiogenesis, cell proliferation, cell migration, and apoptosis. The protein–protein interaction network and module analysis revealed 21 hub genes, which were enriched in cancer pathways, the cell cycle, the HIF1 signaling pathway, and microRNAs in cancer. The VEGF pathway analysis revealed nine upregulated (IL6, EGFR, VEGFA, SRC, CXCL8, PTGS2, IDH1, APP, and SQSTM1) and five downregulated hub genes (POLR2H, RPS3, UBA52, CCNB1, and UBE2C) linked with several of the VEGF signaling pathway components. The survival analysis showed that three upregulated hub genes (CXCL8, VEGFA, and IDH1) were associated with poor survival. The results predict that these hub genes associated with the GBM resistance to bevacizumab may be potential therapeutic targets or can be biomarkers of the anti-VEGF resistance of GBM.

State of the art and up-and-coming angiogenesis inhibitors for ovarian cancer

Angiogenesis inhibitors have clearly shown activity in ovarian cancer in various settings; however, preliminary data did not reflect significant survival benefit. Bevacizumab has been extensively studied and is approved for use in ovarian malignancy. However, the efficacy of bevacizumab is modest and most treated patients eventually develop acquired resistance, which highlights the need for new targeted therapies and/or combination strategies. Newer therapies are being evaluated and their role of these newer therapies is upcoming and promising. Recent research focuses on the role of this drug group in frontline, maintenance and recurrent settings. Combination of PARP inhibitors with angiogenesis inhibitors has recently shown to improved survival rates. Potential strategies need to be devised for selecting patients most likely to benefit from such therapy.