The Role of Autophagy in Cancer Evolution and Prognosis, Highlighting Its Role in PCa and Its Interaction with Apoptosis and Epigenetic Regulation by miRNAs

Abstract

Background: Autophagy is a process that diversely impacts the stages of both tumor initiation and progression. Elucidating the molecular mechanisms underlying autophagy and its role in tumorigenesis is a key component of anticancer strategies in both prostate cancer and other malignancies. Because advanced prostate cancer frequently exploits enhanced autophagy as a defense mechanism against therapy-induced stress (e.g., from abiraterone), the pharmacological modulation of miRNA levels presents a tremendous opportunity to block the tumor’s escape route and overcome drug resistance. Methods: A comprehensive literature review was conducted to evaluate the molecular pathways determining cancer cell survival and death. The analysis focused on the dual nature of autophagy (functioning as a ‘double-edged sword’) within the tumor microenvironment, microRNA (miRNA) regulatory networks, and the efficacy of synergistic therapeutic strategies in overcoming treatment resistance. Results: The primary focus of this paper is the dual and complex role of autophagy, which serves, on the one hand, as a cellular protective shield against metabolic stress—thereby facilitating metastasis—and, on the other hand, as a potential pathway leading to autophagic cell death. The progression of this crucial process is regulated by intricate interactions (crosstalk) with apoptotic pathways, mediated by Bcl-2 family proteins, key kinases (such as mTOR, JNK, and DAPK), and transcription factors, such as p53. Furthermore, the autophagic machinery is precisely regulated by specific miRNA molecules (e.g., miR-21, miR-141, and miR-375). These not only act as crucial intracellular modulators of autophagy but also serve as promising circulating biomarkers, enabling the monitoring of this process’s activity throughout disease progression. Conclusions: Autophagy, and in particular its modulation via miRNA signaling networks, represents a major and highly promising translational target. By directly impairing this autophagic survival mechanism, ‘double-hit’ combination therapies—integrating autophagy inhibitors (such as hydroxychloroquine or VPS34 inhibitors) with standard antiandrogen or cytotoxic agents—demonstrate promising preclinical potential in overcoming treatment resistance and favorably modulating the immune microenvironment in advanced prostate cancer.