Intracellular Nampt impairs esophageal squamous cell carcinoma neo-adjuvant chemotherapy response independent of eNampt.

Nampt consists of iNampt and eNampt, might contribute to modulating obesity-related malignancies and impairing response to chemotherapy in a range of cancers. This study explored the role of Nampt and adiposity in the progression and response to neo-adjuvant chemotherapy of esophageal squamous cell carcinoma (ESCC). Patients with ESCC were treated with 2 cycles of neo-adjuvant chemotherapy, then evaluated for surgery. Tumor regression grading (TRG) and prognosis of these patients were collected. Anthropometry was well utilized. Serum eNampt was determined by enzyme-linked immunosorbent assay, iNampt expression in tissues were assessed by PCR, western blot and immunohistochemistry. eNampt in sera elevated significantly in these over-weight or obese patients, and was positively associated with body mass index (BMI), waist circumference, visceral fat area (VFA), subcutaneous fat area (SFA) and total fat area (TFA) (P<0.05). iNampt expression in the mRNA and protein levels were up-regulated in ESCC compared to their adjacent non-tumor specimens (P<0.05). iNampt protein staining revealed mainly in the cytoplasm and nuclei, while it was not related to serum eNampt, BMI, waist circumference, VFA, SFA and TFA (P>0.05). Pre-treatment iNampt, BMI, SFA, TFA and age significantly correlated with neo-adjuvant chemotherapy response, and iNampt expression and age were independent predictors (P<0.05). Pre-treatment iNampt, ypT, ypN, ypTNM stage and TRG were associated with the survival of ESCCs, and ypN stage and TRG were independent prognostic factors (P<0.05). In conclusion, iNampt impaired ESCC response to neo-adjuvant chemotherapy independent of eNampt, targeting iNampt to increase ESCC response to neo-adjuvant chemotherapy would improve the prognosis of ESCCs. AJTR