M410, a combretastatin A4 analogue, disrupts microtubules and inhibits HIF-1α in human breast cancer cells

Treatment Effect of a Vascular-Disrupting Agent Dynamically Monitored by DWI: An Animal Experimental Study

Objective

To investigate the treatment effect of a vascular-disrupting agent, M410, using diffusion-weighted imaging in a rabbit model of hepatic VX2 tumor.

Methods

28 New Zealand white rabbit models with VX2 liver tumors were established and were randomly divided into M410 (intravenous injection of M410 at a dose of 25 mg/kg every three days) and control (intravenous injection of saline every three days) groups. Conventional and diffusion-weighted imaging (DWI) were acquired on a 3.0 T MR unit at baseline, 4 h, d 1, d 4, d 7, and d 14 posttreatment. B-value with 700 (s/mm2) was chosen during DWI examinations. Tumor volume and apparent diffusion coefficient (ADC) values of the entire tumor and solid component of the tumor at every time point were measured. Two randomly chosen rabbits from each group were sacrificed for H&E staining and CD34 immunohistochemical assessments at each time point. An independent sample t-test was used to assess differences in tumor sizes and ADC values of the entire tumor and solid component of tumors between two groups, with P < 0.05 considered statistically significant.

Result

There was no significant difference in tumor volume between the two groups at baseline, 4 h, and d 1. With time, the tumors in the control group grew significantly faster than those in the M410 group, and the average ADC values of the M410 group were lower than those of the control group at d 1 and higher than those of the control group at d 4; as such, there were statistical differences between the two groups at these two time points but not at the other four time points. The following pathological results reflected the underlying morphological changes and vascular alterations.

Conclusions

M410 performed well in inhibiting the growth of the hepatic VX2 tumor which could be noninvasively monitored by DWI metrics.

Tumorigenesis and Progression As A Consequence of Hypoxic TME：A Prospective View upon Breast Cancer Therapeutic Targets

Intratumoral hypoxia has a significant impact on the development and progression of breast cancer (BC). Rather than exerting limited regional impact, hypoxia create an aggressive macroenvironment for BC. Hypoxia-inducible factors-1(HIF-1) is extensively induced under hypoxia condition of BC, activating the transcription of multiple oncogenes. Thereinto, CD73 is the one which could be secreted into the microenvironment and is in favor of the growth, metastasis, resistance to therapies, as well as the stemness maintenance of BC. In this review, we address the significance of hypoxia/HIF-1/CD73 axis for BC, and provide a novel perspective into BC therapeutic strategies.

The role of hypoxia-inducible factors in neovascular age-related macular degeneration: a gene therapy perspective

Understanding the mechanisms that underlie age-related macular degeneration (AMD) has led to the identification of key molecules. Hypoxia-inducible transcription factors (HIFs) have been associated with choroidal neovascularization and the progression of AMD into the neovascular clinical phenotype (nAMD). HIFs regulate the expression of multiple growth factors and cytokines involved in angiogenesis and inflammation, hallmarks of nAMD. This knowledge has propelled the development of a new group of therapeutic strategies focused on gene therapy. The present review provides an update on current gene therapies in ocular angiogenesis, particularly nAMD, from both basic and clinical perspectives.

PD-L1 protein expression in non-small-cell lung cancer and its relationship with the hypoxia-related signaling pathways: A study based on immunohistochemistry and RNA sequencing data

OBJECTIVES

Therapies that target programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) have shown promising efficacy in non-small-cell lung cancer (NSCLC). Hypoxia-related genes are also important regulators of PD-L1, and the role of PD-L1 in NSCLC is still not clear. The objective of this study was to investigate PD-L1 expression and its correlation with hypoxic-inducible factor 1α (HIF1A), vascular endothelial growth factor A (VEGFA), glucose transporter 1 (GLUT1), and carbonic anhydrase 9 (CAIX) expression in NSCLC patients. The association between PD-L1 expression and survival was also determined.

MATERIALS AND METHODS

PD-L1/protein expression was evaluated in 295 resected NSCLCs and its correlation with HIF1A, VEGFA, GLUT1, CAIX expression and survival was determined based on immunohistochemical and RNA sequencing data obtained from The Cancer Genome Atlas (TCGA) database.

RESULTS

PD-L1 protein expression was significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression only in adenocarcinoma when a 10% or a 50% cut-off was used. PD-L1 mRNA expression was also significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma. Univariate analysis revealed that HIF1A expression was associated with poor recurrence-free survival (RFS), and GLUT1 was associated with poor overall survival (OS) and RFS. GLUT1 was an independent prognostic factor for OS in multivariate analysis of immunohistochemical and TCGA data (p = 0.024 and 0.029, respectively). Patients with low expression of both PD-L1 and GLUT1 had longer OS than other patterns in immunohistochemical and TCGA data (p = 0.003 and 0.051, respectively).

CONCLUSIONS

PD-L1 protein and mRNA expression were correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma alone. Low expression of GLUT1 and low expression of both PD-L1 and GLUT1 were associated with improved prognosis. Our findings support the rationale for co-targeting hypoxia-related genes and PD-L1 in cancer therapy. Expression of hypoxia-related genes may be helpful in selecting patients appropriate for PD-L1 therapy.

Current evidence for cancer stem cells in gastrointestinal tumors and future research perspectives

Cancer stem cells (CSCs) are a very heterogeneous subpopulation of "stem-like" cancer cells that have been identified in many cancers, including leukemias and solid tumors. It is believed that CSCs drive tumor growth, malignant behavior and are responsible for the initiation of metastatic spread. In addition, CSCs have been implicated in chemotherapy and radiotherapy resistance. Current evidence supports the theory that CSCs share at least two main features of normal stem cells: self-renewal and differentiation, properties that contribute to tumor survival even in the presence of aggressive chemotherapy; however, the mechanism(s) governing the unique biology of CSCs remain unclear. In the field of gastrointestinal cancer, where we face very low survival rates across different tumor types, unraveling the role of CSCs in gastrointestinal tumors should improve our knowledge of cancer biology and chemoresistance, ultimately benefiting patient survival. Towards this end, much effort is being invested in the characterization of CSCs as a means of overcoming drug resistance and controlling metastatic spread. In this review we will cover the concept of CSCs, the current evidence for CSCs in gastrointestinal tumors and future research directions.