Angiogenesis and Its Role in the Tumour Microenvironment: A Target for Cancer Therapy

Abstract

The process of angiogenesis refers to the growth of new blood vessels from existing ones. Tumours can produce factors in the micro-environment which act on blood vessels to promote angiogenesis. It is therefore considered to be fundamental in tumour progression and metastatic dissemination. This neovascularization can be regulated by numerous endogenous factors in the tumour micro-environment. As a result, anti-angiogenic therapies have been developed in the hope of targeting this process to reduce tumour growth and progression. However, only a proportion of patients respond to therapy, indicating the presence of treatment resistance in some. In this chapter, we aim to highlight the process of angiogenesis and to review pivotal evidence for the use of anti-angiogenic therapies thus far (alone and in combination with other agents). Finally, we will illustrate recent evidence for the discovery of biomarkers for anti-angiogenic therapies and potential mechanisms of resistance to such agents.

High levels of serum cholesterol positively correlate with the risk of the development of vessel co-opting tumours in colorectal cancer liver metastases

“…Moreover, angiogenesis is the predominant vascularization in DHGP tumours 8 . However, vessel co-option is the prevalent vascularization in RHGP tumours, in which the cancer cells co-opt the pre-existing vessels to obtain the blood supply 8,14 . Previous investigations reported vessel co-option as acquired resistance to anti-angiogenic therapy in various cancers including CRCLM, hepatocellular carcinoma (HCC) and glioblastoma 15 .…”

“…Bevacizumab) 6,7 . However, acquired resistance against these treatments frequently occurs that resulting in treatment failure and cancer recurrence 8 .…”

“…Colorectal cancer liver metastases (CRCLMs) present with two common histopathological growth patterns (HGPs): Desmoplastic HGP (DHGP) and replacement HGP (RHGP) [8][9][10][11] . The fundamental histopathological feature of DHGP lesions is the presence of a desmoplastic rim at the tumour periphery that separates cancer cells from liver parenchyma 8 . However, the desmoplastic rim is absent in RHGP lesions, and the cancer cells infiltrate through adjacent liver plates 8,12,13 .…”

The Role of Beetroot Extract in Overcoming Chemoresistance of Neoadjuvant Adriamycin Cyclophosphamide Regimen by Targeting Immune Response in Tumor Microenvironment: A Preclinical Study in Mammary Adenocarcinoma Rats

“…Asian Pacific Journal of Cancer Prevention, Vol 23 1063 DOI:10.31557/APJCP.2022.23.3.1061 The Role of Beetroot Extract Partial Response = TRG 3, No Response = TRG 4-5 (Frentzas et al, 2019).…”

“…Clinically, pCR assessment can use a variety of different standards. pCR can also be obtained from evaluating the proportion of fibrosis to tumour cells described in the absence of tumour cells and mostly fibrosis, or tumour cells are sparse and scattered throughout the fibrosis (Frentzas et al, 2019).…”