Background/Objectives: Exercise training (ET) can improve wound healing and prevent the recurrence of skin lesions. Aerobic ET stimulates the NAD+-dependent deacetylase sirtuin 1 (SIRT1). The beneficial effects of ET and SIRT1 activation in wound healing have been characterized when considered separately. This study aimed to investigate the potential role of SIRT1 as a mediator of the effects of sera isolated from athletes who regularly participate in aerobic ET (middle-distance running, MDR) on cells primarily involved in wound healing. Methods: Human keratinocytes, fibroblasts and endothelial cells were conditioned with sera from middle-distance runners and age-matched sedentary subjects (sed). Cell motility, angiogenesis and the expression of key biomarkers of cell activation were evaluated in the presence or absence of the selective SIRT1 inhibitor EX-527. Results: Higher SIRT1 activity was detected in all of the cell lines conditioned with the MDR group sera compared with that in the cells in the sed group sera. The involvement of SIRT1 was demonstrated by EX-527’s selective inhibition. Alongside the increase in SIRT1 activity, a marked increase in migration, invasion and angiogenesis was observed. The levels of E-cadherin decreased while those of integrin β1 and vinculin increased in the keratinocytes and fibroblasts conditioned with the MDR group sera compared to these values with the sed group sera, respectively. Increased levels of differentiation markers, such as involucrin in the keratinocytes, FAP1α in the fibroblasts and CD31 in the endothelial cells, were observed with the MDR group sera compared to these values using the sed group sera. Conclusions: The ex vivo/in vitro approach used here links aerobic ET-induced SIRT1 activity to proper tissue regeneration.

Background: the treatment of squamous cell carcinomas of the oral cavity (OSCCs) is limited by the lack of reliable diagnostic/prognostic, and predictive markers, as well as by intrinsic tumor cell heterogeneity. 5-azacytidine (5-AZA) offers opportunities for cancer cell reprogramming to develop new target-specific treatments. The protein annexin A1 (ANXA1) is downregulated in head and neck squamous cell carcinoma (HNSCC), correlated with pathological differentiation grade. Objectives: this work aimed to further investigate the role of ANXA1 in OSCC progression based on 5-AZA activity. Methods: we used CAL27 and CAL33 cell lines, which differ in drug sensitivity and differentiation status. Results: CAL27 showed a higher expression of the stemness markers compared to CAL33 cells, but this positivity was lost after treatment with 5-AZA. This drug also decreased CAL27 cell motility, promoting a less aggressive phenotype. Moreover, 5-AZA increased ANXA1 expression only in CAL27. After siRNA-mediated downmodulation, we witnessed a significant rise in cell motility and the inversion of E-/N-cadherin expression, which was reverted again by 5-AZA. To investigate the role of exogenous ANXA1 derived from the tumor microenvironment, we treated CAL27 with Ac2-26, an ANXA1 mimetic peptide. Interestingly, we found that this peptide alone showed impacts similar to 5-AZA in reversing the aggressive phenotype. All these effects were not evidenced in CAL33 cells. Finally, to prove the loop of the exogenous protein, we detected increased expression of its receptors, formyl peptide receptors (FPRs), and their activation, leading to oncosuppressor effects. Conclusions: we propose that ANXA1 mediates the effects of 5-AZA only in poorly differentiated stemlike CAL27 cell lines. This suggests the relevance of ANXA1 as a diagnostic/prognostic biomarker in OSCCs, paving the way for personalized therapies to overcome treatment difficulties.

Pancreatic carcinoma (PC) is the most lethal malignancy due to its aggressive behavior and limited therapeutic response. Among the annexin family, Annexin A1 (ANXA1) is documented to promote PC aggressiveness, and conversely, the role of Annexin A6 (ANXA6) is less explored. Here, we report that ANXA6 is significantly upregulated in ANXA1 knockout (KO) MIA PaCa-2 cells. Using LAM20, our previously identified ANXA6 modulator, we show that inhibition of this protein impairs cell motility, and epithelial-to-mesenchymal transition markers, without affecting 2D/3D cell proliferation. ANXA6 siRNA-mediated knockdown reproduces LAM20 effects, suggesting a relationship with their impact on ANXA6. Interestingly, in ANXA1 KO cells, LAM20 reduced the migration/invasion rate differently from the ANXA1 inhibitor heparan sulfate, which retains effects on the wild-type (WT) MIA PaCa-2 counterpart. These findings suggest that in cells lacking ANXA1, ANXA6 plays a compensatory role in sustaining the aggressive phenotype, albeit to a lesser extent than in WT cells. Thus, LAM20 represents a promising therapeutic strategy to impair PC aggressiveness. Our study provides new insights into ANXA1/ANXA6 crosstalk and introduces a novel approach to disturb PC pro-invasive mechanisms. Targeting ANXA1 and ANXA6 is relevant because, where ANXA1 is downregulated/absent, ANXA6 expression can be restored in a compensatory manner, partially sustaining tumor progression.