Significant WLI vs. AC differences were seen in baseline-to-follow-up changes in weight (-3.62 vs. -0.52 kg), %body fat (-1.3 vs. 0%), moderate-to-vigorous physical activity (+224 vs. +115 min/week), caloric density (-0.3 vs. 0 kcal/g), serum leptin (-12.3 vs. -4.0 ng/dl) and upregulation of tumor PI3Kinase signaling and cell cycle-apoptosis related genes (CC-ARG; all p-values <0.05).
Leptin is a nutritional cytokine encoded by the obesity gene whose concentration in the tumor microenvironment is closely related to the occurrence and progression of cancer.
Engineering oncolytic viruses to express leptin in tumor cells induced complete responses in tumor-bearing mice and supported memory development in the tumor infiltrate.
Collectively, these studies demonstrate that although MDSC protect against some metabolic dysfunction associated with HFD they enhance tumor growth in HFD mice and that leptin is a key regulator linking HFD, chronic inflammation, immune suppression, and tumor progression.
A growing body of evidence suggests an important role of leptin in our major obesity-related health issues such as insulin resistance, hypertension, and neoplasia.
The profiles were tested on 1) snap-frozen tumors from 133 patients with completely resected stage 1B-2 NSCLC randomized to adjuvant cisplatin and vinorelbine (ACV, n = 71) or no adjuvant treatment (OBS, n = 62) and 2) formalin-fixed paraffin-embedded (FFPE) tumors from 95 patients with completely resected stage 1A-3B NSCLC receiving adjuvant cisplatin and vinorelbine.
Leptin stimulated migration and invasion of cultured HCT-116 cells and tumor growth in the xenograft assay, and these effects were abrogated by a SIRT1 inhibitor sirtinol, suggesting that SIRT1 plays a role in leptin-induced colon carcinogenesis.
Hence, the current findings suggest that acute treatments of tumor Leydig cells with high levels of leptin have negligible effects on transcriptomics and rather supports that leptin would have a central effect on the hypothalamus to influence testicular function.
Thus, immunohistochemical staining of leptin in colorectal cancer could be a helpful tool in the prediction of prognosis and survival pattern of colorectal cancer with certain clinicopathological factors (tumor size, lymphovascular invasion, distant metastasis, local recurrence, and relapse of disease).
In the present study, the function of a leptin-derived peptide (LP16, 91-110 of Leptin) was investigated as a targeting ligand to decorate PEGylated liposomal doxorubicin (PLD, Doxil<sup>®</sup>) surface and the anti-tumor activity and therapeutic efficacy of Doxil in C26 (Colon Carcinoma) tumor model were also evaluated.
Diagnostic values of leptin and galectin-3 with regard to differentiation between high (Fédération Internationale de Gynécologie Obstétrique [FIGO] III and IV) and low (FIGO I and II) stages of clinical tumor advancement and prediction of tumor grading (G1 vs G3) based on the AUC curve were 0.82/0.70 and 0.80/0.74.
This exploratory study was carried out to determine the expression levels of hepatocyte growth factor (HGF), insulin-like growth factor 1, thyroid-stimulating hormone (TSH), and leptin in serum and tumor samples from patients with uveal melanoma and to investigate the potential association of these expression levels with disease progression and patient survival.
Vasculogenic mimicry (VM) was an important tumor blood supply to complement the endothelial cell-dependent angiogenesis, while leptin and receptor (ObR) involved in angiogenesis in glioblastoma has been reported on previous study, but the relationship between ObR expression and VM formation in human glioblastoma tissues, as well as their prognostic significance still remains unclear.
Furthermore, pathway analysis of these transcripts demonstrated their association with active inflammation and colon cancer signaling, with leptin and Wnt as the top two transcripts elevated in mouse HFD colon shared with tumors.
The results demonstrated a statistically significant increase in the level of leptin in plasma samples from the tumor microenvironment of obese patients with estrogen receptor positive (ER+) breast cancer, compared with peripheral plasma samples.
Therefore, we hypothesize that over-expression of LEPR, rather than that of LEP has a fundamental role in breast carcinogenesis in particular, and probably for LEP-LEPR associated tumors in general.
Collectively, the studies suggest that breastfeeding might be negatively associated with promoter methylation of LEP (which encodes an anorexigenic hormone), CDKN2A (involved in tumour suppression) and Slc2a4 genes (which encodes an insulin-related glucose transporter) and positively with promoter methylation of the Nyp (which encodes an orexigenic neuropeptide) gene, as well as influence global methylation patterns and modulate epigenetic effects of some genetic variants.
Although the underlying pathological mechanisms of leptin's association with poor prognosis are not clear, leptin can impact the tumor microenvironment in several ways.
In triple-negative breast cancer (TNBC), LEP is hypothesized to predominantly mediate its tumorigenic effects via a subpopulation of LEPRb-positive tumor cells termed cancer stem cells (CSCs) that can initiate tumors and induce tumor progression.