Understanding the function of the tumor microenvironment,and compounds from marine organisms for breast cancer therapy

The pathology and physiology of breast cancer(BC),including metastasis,and drug resistance,is driven by multiple signaling pathways in the tumor microenvironment(TME),which hamper antitumor immunity.Recently,long non-coding RNAs have been reported to mediate pathophysiological developments such as metastasis as well as immune suppression within the TME.Given the complex biology of BC,novel personalized therapeutic strategies that address its diverse pathophysiologies are needed to improve clinical outcomes.In this review,we describe the advances in the biology of breast neoplasia,including cellular and molecular biology,heterogeneity,and TME.We review the role of novel molecules such as long non-coding RNAs in the pathophysiology of BC.Finally,we provide an up-to-date overview of anticancer compounds extracted from marine microorganisms,crustaceans,and fishes and their synergistic effects in combination with other anticancer drugs.Marine compounds are a new discipline of research in BC and offer a wide range of anti-cancer effects that could be harnessed to target the various pathways involved in BC development,thus assisting current therapeutic regimens.

Tumor microenvironment pathways:Cross regulation in breast cancer metastasis

The tumor microenvironment(TME)is heterogeneous and contains a multiple cell population with surrounded immune cells,which plays a major role in regulating metastasis.The multifunctional pathways,Hedgehog(Hh),Wnt,Notch,and NF-kB,cross-regulates metas-tasis in breast cancer.This review presents substantial evidence for cross-regulation of TME components and signaling pathways,which makes breast TME more heterogeneous and com-plex,promoting breast cancer progression and metastasis as a highly aggressive form.We discoursed the importance of stromal and immune cells as well as their crosstalk in bridging the metastasis.We also discussed the role of Hh and Notch pathways in the intervention be-tween breast cancer cells and macrophages to support TME;Notch signaling in the bidirec-tional communication between cancer cells and components of TME;Wnt signal pathway in controlling the factors responsible for EMT and NF-kB pathway in the regulation of genes con-trolling the inflammatory response.We also present the role of exosomes and their miRNAs in the cross-regulation of TME cells as well as pathways in the reprogramming of breast TME to support metastasis.Finally,we examined and discussed the targeted small molecule inhibitors and natural compounds targeting developmental pathways and proposed small molecule nat-ural compounds as potential therapeutics of TME based on the multitargeting ability.In conclu-sion,the understanding of the molecular basis of the cross-regulation of TME pathways and their inhibitors helps identify molecular targets for rational drug discovery to treat breast can-cers.