[Expression of SOX-11 and TFE3 in solid-pseudopapillary tumor of pancreas and its clinical significance]

Objective: To investigate the expression status and diagnostic value of SRY related high mobility group box 11 (SOX-11) and transcription factor E-3 (TFE3) in solid pseudopapillary tumors of pancreas (SPTPs). Methods: Thirty-eight cases of SPTPs, 36 cases of well-differentiated pancreatic neuroendocrine tumors (PanNETs) and six cases of pancreatic acinar cell carcinomas (PACCs) were collected at the Affiliated Drum Tower Hospital of Nanjing University Medical School from 2012 to 2019. The expression of SOX-11, TFE3 and β-catenin was detected by immunohistochemistry, and the TFE3 gene status was detected by FISH in 18 cases of SPTPs. Results: Among the 38 SPTP patients, 29 were female and 9 were male, with a mean age of 50 years; among 36 PanNET patients, 32 were female and 4 were male, with a mean age of 39 years; for the six PACC patients, four were male and two were female, with a mean age of 60 years. β-catenin was positive in all 38 SPTPs, but was negative in all 36 PanNETs and 5/6 PACCs. SOX-11 was positive in 35/38 (92.1%) of SPTPs, but was negative in all 36 PanNETs and 6 PACCs. TFE3 was positive in 36/38 (94.7%) of SPTPs, but was negative in all 36 PanNETs and 6 PACCs. Among these three tumors, the specificity and sensitivity of β-catenin were 97.6% and 100.0%, the specificity and sensitivity of SOX-11 were 92.1% and 100.0%, the specificity and sensitivity of TFE3 were 94.7% and 100.0%, respectively. There was a significant difference of the expression status of all three markers in SPTPs compared with PanNETs and PACCs (P<0.01). The results of SOX-11 and TFE3 immunostaining showed high consistency (Kappa>0.6). No gene rearrangement (0/18) of TFE3 was found in SPTPs. Conclusion: SOX-11 and TFE3 are highly expressed in SPTPs, and their specificity in the differential diagnosis of SPTPs is better than that of β-catenin.

Enhanced Chondrogenic Capacity of Mesenchymal Stem Cells After TNFα Pre-treatment

Mesenchymal stem cells (MSCs) are promising cells to treat cartilage defects due to their chondrogenic differentiation potential. However, an inflammatory environment during differentiation, such as the presence of the cytokine TNFα, inhibits chondrogenesis and limits the clinical use of MSCs. On the other hand, it has been reported that exposure to TNFα during in vitro expansion can increase proliferation, migration, and the osteogenic capacity of MSCs and therefore can be beneficial for tissue regeneration. This indicates that the role of TNFα on MSCs may be dependent on the differentiation stage. To improve the chondrogenic capacity of MSCs in the presence of an inflamed environment, we aimed to determine the effect of TNFα on the chondrogenic differentiation capacity of MSCs. Here, we report that TNFα exposure during MSC expansion increased the chondrogenic differentiation capacity regardless of the presence of TNFα during chondrogenesis and that this effect of TNFα during expansion was reversed upon TNFα withdrawal. Interestingly, pre-treatment with another pro-inflammatory cytokine, IL-1β, did not increase the chondrogenic capacity of MSCs indicating that the pro-chondrogenic effect is specific for TNFα. Finally, we show that TNFα pre-treatment increased the levels of SOX11 and active β-catenin suggesting that these intracellular effectors may be useful targets to improve MSC-based cartilage repair. Overall, these results suggest that TNFα pre-treatment, by modulating SOX11 levels and WNT/β-catenin signaling, could be used as a strategy to improve MSC-based cartilage repair.