Single versus dual venous anastomosis in radial forearm free flaps in head and neck reconstruction.

A retrospective cohort study of 253 radial forearm free flap (RFFF) procedures in head and neck reconstruction performed in our department between 2005 and 2018 was reviewed. In order to explore the effects between single and dual anastomoses, we applied Fisher's exact test for statistical analysis. Although no flap failure was identified, more venous compromises were observed in single anastomosis group (5/80 vs. 1/173). We conclude that dual venous anastomoses can reduce venous compromise resulted from unexpected causes in RFFF transfer. Therefore, we especially recommend dual venous anastomoses for those who cannot withstand a second surgery.

Abnormal downregulation of 10-formyltetrahydrofolate dehydrogenase promotes the progression of oral squamous cell carcinoma by activating PI3K/Akt/Rb pathway.

BACKGROUND: 10-formyltetrahydrofolate dehydrogenase (ALDH1L1) is a major folate enzyme, which is usually underexpressed in malignant tumors and competes with tumors for the same folate substrate. However, the specific role and mechanisms of ALDH1L1 in oral squamous cell carcinoma (OSCC) remainsobscure. METHODS: The expression level of ALDH1L1 in paired OSCC tissues and adjacent noncancerous tissues were detected by quantitative realtime PCR, Western blot and immunohistochemistry. The relationship between ALDH1L1 expression and clinical characteristics was analyzed. Besides, CCK8, EdU staining, colony formation, wound healing, transwell invasion, apoptosis, cell cycle assays and nude mice tumor bearing experiments were employed to assess the role of ALDH1L1 in OSCC. To explore the underlying mechanisms of these effects, cell cycle-related markers were examined. RESULTS: In this study, we revealed that ALDH1L1 expression was significantly reduced in OSCC, and its downregulation was associated with the malignancy of the tumor and poor prognosis of patients. In vivo and in vitro experiments, downregulation of ALDH1L1 in OSCC significantly inhibited the occurrence of NADP+ -dependent catalytic reactions and facilitated tumor cell growth, migration, invasion, survival, cell cycle progression, and xenograft tumor growth. On the contrary, re-expression of ALDH1L1 plays a similar role to anti-folate therapy, promoting NADPH production and suppressing the progression of OSCC. Furthermore, ALDH1L1 overexpressing obviously inhibited the expression of PI3K, p-Akt, CDK2, CDK6, Cyclin D1, Cyclin D3, and Rb in OSCC cells, and promoted the expression of p27. LY294002 and 740 Y-P were used to confirm the inhibitory effects of ALDH1L1 on OSCC progression through PI3K/Akt/Rb pathway. CONCLUSION: Our findings highlight the clinical value of ALDH1L1 as a prognostic marker and the potential of a new target for anti-folate therapy.