TSP-1 as a novel biological marker of tumor vasculature normalization in colon carcinoma induced by Endostar

Alleviating hypoxia to improve cancer immunotherapy

Tumor hypoxia resulting from abnormal and dysfunctional tumor vascular network poses a substantial obstacle to immunotherapy. In fact, hypoxia creates an immunosuppressive tumor microenvironment (TME) through promoting angiogenesis, metabolic reprogramming, extracellular matrix remodeling, epithelial-mesenchymal transition (EMT), p53 inactivation, and immune evasion. Vascular normalization, a strategy aimed at restoring the structure and function of tumor blood vessels, has been shown to improve oxygen delivery and reverse hypoxia-induced signaling pathways, thus alleviates hypoxia and potentiates cancer immunotherapy. In this review, we discuss the mechanisms of tumor tissue hypoxia and its impacts on immune cells and cancer immunotherapy, as well as the approaches to induce tumor vascular normalization. We also summarize the evidence supporting the use of vascular normalization in combination with cancer immunotherapy, and highlight the challenges and future directions of this overlooked important field. By targeting the fundamental problem of tumor hypoxia, vascular normalization proposes a promising strategy to enhance the efficacy of cancer immunotherapy and improve clinical outcomes for cancer patients.

MicroRNA-3907 promotes the proliferation and migration of sebaceous gland carcinoma of the eyelid by targeting thrombospondin 1

MicroRNAs (miRNAs/miRs) play an important role in various types of carcinoma, including sebaceous gland carcinoma (SGC) of the eyelid. miR-3907 was found to be highly expressed in lung cancer; however, to the best of our knowledge, the biological role of miR-3907 in SGC has not previously been evaluated. The aim of the present study was to determine the role and mechanism of miR-3907 in the occurrence and development of SGC. miR-3907 was screened and identified as a novel upregulated miRNA in SGC tissues and cells, as determined using miRNA microarrays and reverse transcription-quantitative (RT-q) PCR analyses. Compared with the control group, cellular proliferation and migration were enhanced in the miR-3907 mimics group, and decreased in the miR-3907 inhibitor group. Moreover, miR-3907 negatively regulated thrombospondin 1 (THBS1) expression, as shown by bioinformatics prediction, RT-qPCR, western blotting and dual-luciferase reporter assays. In addition, compared with the control group, the small interfering (si) siRNA-THBS1 group exhibited enhanced proliferation and migration abilities, which were decreased in the THBS1 overexpression group. Furthermore, THBS1 overexpression was found to attenuate the stimulative effect of miR-3907 mimics, and THBS1-knockdown reversed the inhibitory effect of the miR-3907 inhibitor in SGC cells. Collectively, the results of the present study indicated that miR-3907 promoted the proliferation and migration of SGC by downregulating THBS1, and that this axis may be a potential target for the prognostic assessment and treatment of SGC.

Vascular Normalization: A New Window Opened for Cancer Therapies

Preclinical and clinical antiangiogenic approaches, with multiple side effects such as resistance, have not been proved to be very successful in treating tumor blood vessels which are important targets for tumor therapy. Meanwhile, restoring aberrant tumor blood vessels, known as tumor vascular normalization, has been shown not only capable of reducing tumor invasion and metastasis but also of enhancing the effectiveness of chemotherapy, radiation therapy, and immunotherapy. In addition to the introduction of such methods of promoting tumor vascular normalization such as maintaining the balance between proangiogenic and antiangiogenic factors and targeting endothelial cell metabolism, microRNAs, and the extracellular matrix, the latest molecular mechanisms and the potential connections between them were primarily explored. In particular, the immunotherapy-induced normalization of blood vessels further promotes infiltration of immune effector cells, which in turn improves immunotherapy, thus forming an enhanced loop. Thus, immunotherapy in combination with antiangiogenic agents is recommended. Finally, we introduce the imaging technologies and serum markers, which can be used to determine the window for tumor vascular normalization.