To better understand the link between obesity and prostate cancer (PC) aggressiveness, we investigate the role of leptin, an obesity associated adipokine, and its receptor (Ob-R) in PC cells migration. The migration assay (Wound-healing) was used to study the leptin impact on DU-145 and PC3 cells lines. STAT3 activation was performed by Western Blot. E-cadherin expression was studied using fluorescence microscopy and Ob-R expression in PC and benign prostatic Hyperplasia (BPH) biopsies was assessed by RT-PCR. In this study we demonstrate that high dose of leptin promotes PC cells migration and EMT transition via the stimulation of STAT3 pathway. In addition, we report that although Ob-R mRNA is expressed by ADK and BPH resections biopsies, significant higher levels were observed for ADK patients. Finally, we found a positive association between Ob-R mRNA expression and worse PC prognosis. A better understanding of the molecular processes of leptin signaling is crucial for identifying appropriate approaches for treatment of obesity-related PC patients.

Large prospective studies established a link between obesity and breast cancer (BC) development. Yet, the mechanisms underlying this association are not fully understood. Among the diverse adipocytokine secreted by hypertrophic adipose tissue, leptin is emerging as a key candidate molecule linking obesity and cancer, since it promotes proliferation and invasiveness of tumors. However, the potential implication of leptin on tumor escape mechanisms remains unknown. This study aims to explore the effect of leptin on tumor resistance to NK lysis and the underlying mechanism. We found that leptin promotes both BC resistance to NK92-mediated lysis and β oxidation on MCF-7, by the up-regulation of a master regulator of mitochondrial biogenesis, the peroxisome proliferator activated receptor coactivator-1 α (PGC1A). Using adenoviral approaches, we show that acute elevation of PGC1A enhances the fatty acid oxidation pathway and decreases the susceptibility of BC cells to NK92-mediated lysis. Importantly, we identified the involvement of PGC1A and leptin in the regulation of hypoxia inducible factor-1 alpha (HIF1A) expression by tumor cells. We further demonstrate that basal BC cells MDA-MB-231 and BT-20 exhibit an increased PGC1A mRNA level and an enhanced oxidative phosphorylation activity; in comparison with luminal BC cells MCF7 and MDA-361, which are associated with more resistance NK92 lysis. Altogether, our results demonstrate for the first time how leptin could promote tumor resistance to immune attacks. Reagents blocking leptin or PGC1A activity might aid in developing new therapeutic strategies to limit tumor development in obese BC patients.

Background/Objectives: Obesity-associated hyperleptinemia has been linked to breast cancer (BC) progression via mechanisms that remain incompletely understood. This study explores the role of leptin and its receptor (LEPR) in facilitating BC cell proliferation, migration, epithelial–mesenchymal transition (EMT), and STAT3 signaling pathway activation. Methods: We analyzed gene expression and survival data from TCGA BRCA dataset. MCF-7 and MDA-MB-231 BC cells were exposed to leptin at 10 ng/mL (lean-associated levels) and 100 ng/mL (elevated levels linked to obesity). MTT assays, colony formation tests, wound-healing and tumor spheroid dissemination experiments evaluated cell proliferation and migration. Immunofluorescence and Western blot analysis assessed changes in EMT markers and cytoskeletal alterations, while Western blotting and qPCR assessed STAT3 and NCOA1 expression and activation levels. Results: Elevated LEPR expression was linked with unfavorable prognosis in BC patients. Higher doses of leptin (100 ng/mL) significantly enhanced cellular proliferation rates and migratory capabilities, in both cell lines, and promoted EMT characteristics marked by downregulated E-cadherin and cytoskeleton structural changes. Whereas heightened JAK2/STAT3 signaling correlated with elevated leptin dosages, STAT3 inhibition using AG490 reversed leptin-induced migration while reinstating E-cadherin levels to baseline. Furthermore, leptin upregulated NCOA1, an essential STAT3 coactivator, facilitating increased expression of Cyclin D1 and VEGF target genes. Clinical positive relationships were seen between LEP/LEPR expressions and NCOA1 levels and between NCOA1 and various gene signatures related to STAT3/P-STAT3 within BC specimens. Conclusions: Obesity-associated hyperleptinemia enhances aggressiveness in BC through a mechanism involving LEPR-mediated activation pathways encompassing NCOA1/STAT3, which drive proliferation, migration, and EMT. This assigns a potential therapeutic utility for obesity-related advancements found within BC pathology.

Marine-derived natural products are increasingly recognized for their therapeutic potential in cancer and other chronic diseases. Despite significant advances, current cancer treatments remain challenged by toxicity, drug resistance, and limited survival benefits. Natural compounds offer promising alternatives due to their multi-target mechanisms and favorable safety profiles. Among them, Spirulina, a filamentous cyanobacterium, stands out for its rich composition and diverse biological activities. Its anticancer effects involve apoptosis induction via intrinsic and extrinsic pathways, cell cycle arrest at G1/S or G2/M phases, inhibition of angiogenesis through the VEGF/VEGFR2 axis, and suppression of epithelial–mesenchymal transition. These activities are mainly attributed to C-phycocyanin, allophycocyanin, phenolic compounds, and immunomodulatory polysaccharides. Spirulina also exhibits potent immunomodulatory effects by enhancing natural killer cell activity, promoting M1 macrophage polarization, and regulating Th1 and Th17 cytokine responses, highlighting its potential as both an immunotherapeutic and chemoprotective agent. Moreover, preclinical findings suggest it may reduce chemotherapy-associated side effects. However, translation into clinical therapy remains limited by low bioavailability, lack of standardized extracts, and scarce clinical evidence. This review summarizes current mechanistic and immunological insights and highlights the need for optimized formulations, defined dosing strategies, and well-designed clinical trials to validate Spirulina’s potential in cancer treatment.