Clinical significance of the expression of FOXP3 and TIGIT in Merkel cell carcinoma.

The pathogenesis of 80% of Merkel cell carcinoma (MCC) cases is associated with Merkel cell polyomavirus (MCPyV). Forkhead helix transcription factor P3 (FOXP3) and the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT)-CD155 pathway, which are targets for immunotherapy, were assessed as prognostic factors of MCC. We analyzed mRNA expression data of 111 patients with MCC and performed immunohistochemical analysis to detect the expression of programmed death ligand 1 (PD-L1), CD8, FOXP3, TIGIT, and CD155 in 65 cases of MCC. In CD8 and FOXP3 immunostaining, the number of expressing-infiltrating cells was determined by dividing the region into tumor center and invasive front areas. FOXP3 expression was evaluated separately in cells with high and low intensities. Aberrant TIGIT expression and weak CD155 staining were observed in MCC cells. CD8- and FOXP3-positive cell infiltrations were higher in the invasive front than in the tumor center. Multivariate Cox hazard analysis revealed that high infiltration of cells with low-intensity FOXP3 expression in the invasive front is a favorable prognostic factor (p = 0.025). Thus, targeting TIGIT-CD155 signaling and FOXP3 as well as PD-L1 may be a therapeutic strategy for MCC.

HPV Infection in Squamous Cell Carcinoma of the Hypopharynx, Larynx, and Oropharynx With Multisite Involvement.

The prevalence and prognostic significance of high-risk human papillomavirus (HR-HPV) have been well-established in oropharyngeal squamous cell carcinoma (OPSCC), but not in hypopharyngeal squamous cell carcinoma (HPSCC) or laryngeal squamous cell carcinoma (LSCC). Moreover, HR-HPV infection in squamous cell carcinoma with multisite involvement has not been examined. To clarify these issues, we retrospectively collected 480 invasive tumors from 467 patients with HPSCC, LSCC, or OPSCC, and comprehensively analyzed the detailed tumor localization, transcriptionally active HR-HPV infection by messenger RNA in situ hybridization, and immunohistochemical staining for p16 and Rb. HR-HPV infection was observed in 115/480 tumors (24%). Human papillomavirus (HPV)-positive cases were closely related with p16 positivity and the partial loss pattern of Rb. HR-HPV was detected in 104 of 161 tumors (64.6%) in the pure OPSCC group and only 1 of 253 tumors (0.4%) in the pure HP/LSCC group; the positive case occurred in the vocal cords. In the multisite-involving combined-type squamous cell carcinoma group, HPV infection was observed in 10/40 (25%) cases, and the 10 HPV-positive cases had OPSCC extending to the larynx or hypopharynx. Among high T-stage (T3/T4) cases of pure OPSCC, HPV-positive cases showed a better prognosis ( P =0.0144), whereas the HPV-positive combined OPSCC group did not show a better prognosis ( P =0.9428), as compared with HPV-negative counterpart. The results suggest that HR-HPV infection in pure HPSCC and LSCC may be extremely rare. HR-HPV infection seems to be present in a substantial proportion of patients with combined OPSCC and HPSCC/LSCC, but it may not improve prognosis at such advanced disease stages. Confirmation of these points awaits future studies with larger cohorts.

Comparison of Akt/mammalian target of rapamycin/4E-binding protein 1 pathway signal activation in round stromal and surface cells in patients with sclerosing pneumocytoma.

Sclerosing pneumocytoma (SP) is a rare benign epithelial tumor of the lung, and approximately 40 % of patients with SP present with AKT1 E17K mutation. SP cells comprise proliferated surface and round stromal cells. To elucidate the role of signal transductions and to identify the difference between surface and stromal cells, the current study aimed to investigate the activation of the Akt/mammalian target of rapamycin (mTOR)/4E-binding protein 1 signaling pathway in SP. METHODS: The molecular and pathological characteristics of SP in 12 patients were analyzed. AKT1 gene analysis revealed AKT1 E17K mutation in four cases. Immunohistochemical analysis revealed that tumor cells were cytoplasmic positive for pAkt, pmTOR, p4EBP1, and pS6RP. The surface cells had a significantly higher expression of pmTOR (p = 0.002) and a significantly lower expression of p4EBP1 (p = 0.017) than stromal cells. SP without AKT1 E17K mutation had a higher positive correlation with pacts, p4EBP1, pmTOR, and pS6RP expression than SP with AKT1 E17K mutation. These findings may be attributed to the aberrant activation of the Akt/mTOR pathway due to AKT1 E17K mutations. Hence, both surface and round stromal cells have tumorigenic characteristics, and differences in these characteristics may contribute to variations in tumor growth and the morphology and angiogenesis of SP.

Both type I and type III interferons are required to restrict measles virus growth in lung epithelial cells.

Measles virus (MeV) first infects immune cells in the respiratory tract of a human host, spreads to lymphoid organs throughout the body, and finally enters and grows in respiratory epithelial cells before being released and transmitted to the next host. Thus, efficient growth in respiratory epithelial cells is important for the person-to-person transmission of MeV. Upon viral entry, host cells detect viral nucleic acids and produce interferons (IFNs) to control viral growth. Type I (IFN-α/ß) and type III (IFN-λ) IFNs have largely common induction and signaling mechanisms and stimulate expression of similar target genes but utilize distinct receptors. To determine the relative contributions of type I and type III IFNs to the control of MeV growth in epithelial cells, we examined the growth of MeV and that of its mutants lacking either type I or type III IFN receptor in the human lung epithelial cell line H358. Our results revealed that both type I and type III IFNs are required to restrict MeV growth in H358 cells and that the induction of type III as well as type I IFNs was increased in the absence of the MeV nonstructural V protein.