Abstract
The progression of neoplastic diseases is driven by a complex interplay of biological processes, including uncontrolled proliferation, enhanced invasion, metastasis, and profound metabolic reprogramming. Among the hallmarks of cancer, as revised by Hanahan and Weinberg, the reprogramming of energy metabolism has emerged as a critical feature that enables cancer cells to meet their heightened bioenergetic and biosynthetic demands. One significant aspect of this metabolic adaptation is the accumulation of lipid droplets (LDs) dynamic, cytoplasmic organelles primarily involved in lipid storage and metabolic regulation. LDs serve as reservoirs of neutral lipids and play a multifaceted role in cancer cell physiology. Their accumulation is increasingly recognized as a marker of tumor aggressiveness and poor prognosis. By storing lipids, LDs provide a readily accessible source of energy and essential building blocks for membrane synthesis, supporting rapid cell division and growth. Moreover, LDs contribute to cellular homeostasis by modulating oxidative stress, maintaining redox balance, and regulating autophagy, particularly under nutrient-deprived or hypoxic conditions commonly found in the tumor microenvironment. Importantly, LDs have been implicated in the development of resistance to cancer therapies. They protect cancer cells from the cytotoxic effects of chemotherapeutic agents by buffering endoplasmic reticulum (ER) stress, inhibiting apoptosis, and facilitating survival pathways. The presence of LDs has been shown to correlate with increased resistance to a variety of chemotherapeutic drugs, although the precise molecular mechanisms underlying this phenomenon remain incompletely understood. Emerging evidence suggests that chemotherapy itself can induce changes in LD accumulation, further complicating treatment outcomes. Given their central role in cancer metabolism and therapy resistance, LDs represent a promising target for therapeutic intervention. Strategies aimed at disrupting lipid metabolism or inhibiting LD biogenesis have shown potential in sensitizing cancer cells to chemotherapy and overcoming drug resistance. In this review, we comprehensively examine the current understanding of LD biology in cancer, highlight studies that elucidate the link between LDs and drug resistance, and discuss emerging approaches to target lipid metabolic pathways to enhance therapeutic efficacy across diverse cancer types.