Trop2 is considered to have an important function in tumor metastasis and the promotion of epithelial‑mesenchymal transition (EMT). E‑cadherin is a crucial factor in intercellular adhesion and EMT transformation. In the present study, we detected the expression of Trop2 and E‑cadherin in breast cancer (BC) to better define their prognostic value. The mRNA expression levels of these two genes in 20 cases of fresh BC tissues were detected by quantitative real‑time polymerase chain reaction (qRT‑PCR). We also detected the expression levels of these two genes by immunohistochemistry (IHC) in 312 BC tissues, and the correlations between the expression of these two genes and the clinicopathological characteristics in BC patients were analyzed. The mRNA and protein expression levels of the two genes in BC cell lines were studied by qRT‑PCR and western blotting. The results indicated that Trop2+/E‑cadherin‑ was expressed in BC tissues more than that in the matched adjacent tissues. The protein expression results obtained via IHC were similar to the mRNA expression results. Trop2+/E‑cadherin‑ that was expressed in BC was associated with lymph node status, metastasis, tumor‑node‑metastasis (TNM) stage, and ER‑/PR‑/HER2‑ expression. BC patients that expressed Trop2+/E‑cadherin‑ had poor overall survival rates. The results of Trop2 and E‑cadherin expression levels obtained in the BC cell lines were the same as those obtained in the BC tissues. Overall, Trop2 has a potential role in the promotion of EMT in BC and it could be considered as a therapeutic target in the future.

The present study elucidates the potential role of Trop2 in tumor invasion and the promotion of epithelial‐mesenchymal transition (EMT) when binding β‐catenin in GC. The role of Trop2 in promoting EMT in GC cells was examined by a variety of experimental assays. Moreover, the underlying molecular mechanism of Trop2 in promoting EMT was studied by in vivo and in vitro assays. The Trop2 expression in relation to tumor metastasis status was detected by IHC in 248 cases of GC tissues and 86 cases of matched adjacent tissues. Trop2 promoted the metastasis and induces EMT in GC. Meanwhile, the elevated protein levels of Trop2 and mesenchymal markers were also found in the TGF‐β1‐induced EMT model in GC cells. Importantly, Trop2 physically bound and activated β‐catenin to promote EMT; moreover, Trop2 increased the accumulation of β‐catenin in the nucleus to accelerate metastasis in GC cells. Inhibition of Trop2 expression in GC cells prevented the migration and invasion of GC cells in vivo. Trop2+/vimentin+ expression was higher in GC tissues than that in matched adjacent tissues, and Trop2+/vimentin+ expression in GC was associated with the differentiation, TNM stage, and distant metastases. These sets of data reveal a novel regulatory network of Trop2 in EMT and GC metastasis, suggesting Trop2 as a useful marker for inducing EMT and metastasis of GC, which may help to lead a better understanding of the pathogenesis of the GC.

Human trophoblastic cell-surface antigen 2 (TROP2) is a cell surface glycoprotein that exhibits high expression in various carcinomas but low or no expression in normal tissues. High TROP2 expression plays an important role in promoting tumor development and aggressiveness, which is correlated with reduced patient survival. However, there are few studies regarding TROP2 in relation to both oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions. The expression of TROP2 protein and mRNA was investigated in OSCC tissues, oral potentially malignant lesion tissues, and normal oral tissues using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). The association between TROP2 expression and clinicopathological characteristics of OSCC was also analyzed, and the prognostic value of TROP2 was evaluated. The expression of TROP2 protein and mRNA were both higher in OSCC tissues than in oral potentially malignant lesion tissues or normal oral tissues. Positive TROP2 expression was related to differentiation, lymph node metastases, TNM stage, perineural infiltration, and vascular invasion. Poor overall survival was associated with high TROP2 expression and other factors associated with poor overall survival including poor differentiation, lymph node metastasis, TNM stage, vascular invasion, and perineural invasion in univariate analyses. TROP2 expression as well as TNM stage and vascular invasion were independent prognostic factors associated with the overall survival of OSCC patients in multivariate analyses. In summary, High TROP2 expression is associated with poor overall survival and serves as an independent prognostic factor in OSCC. The results suggest that TROP2 expression could be an effective prognostic biomarker for OSCC.

The occurrence and development of gastric adenocarcinoma (gADC) is closely related to the interaction between tumor cells and immune cells in the tumor microenvironment (TME). Our objective was to characterize the repertoire of immune cells in the TME of gADC. To analyze the transcriptomic, immune, and spatial information of TME in gADC, we constructed single-cell RNA sequencing, 10 × Genomics V(D)J analysis, multiple immunofluorescence techniques, and OSCmap analysis of 49,765 single cells in seven samples from four gADC patients. Our integrative analysis of B cells demonstrated that a large number of mucosal associated lymphoid tissue (MALT)-B cells were detected in the gADC tissues, which have mature tertiary lymphatic structures (mTLSs), and almost no MALT-B cells in peripheral blood sample. Moreover, MALT-B cells are a class of IgA + plasma cells, which are characterized with high expression of complement pathway activation-related genes. Next, natural killer T (NKT) cells mainly exist in gADC tissues accompanied by mTLSs. This study also classified monocytes/macrophages and epithelial cells into benign and malignant types. Interestingly, CSOmap ( q < .05) and multiple immunofluorescence ( p < .05) results indicated more types of immune cells can be enriched in tissues with mTLSs than normal TLSs, and the density of mTLSs were higher than normal TLSs. Our findings provide novel insights for the signature of immune cells and tumor cells in the TME of gADC with TLSs and highlight the potential importance of IgA-mediated humoral immunity in gADC patients with TLSs.

Most malignant neoplasms of the oral cavity are oral squamous cell carcinoma (OScc), which is a type of highly malignant tumor with a propensity for forming distant metastases. Trophoblast cell surface antigen 2 (TROP2) is a transmembrane protein that is overexpressed in several types of tumor cells, although its role and regulatory mechanism in OScc have not been determined. The aim of the present study was to examine the effects of TROP2 in human OScc cell lines. The present study demonstrated that TROP2 protein expression was upregulated in OScc cell lines. Transfection of short hairpin RNA (shRNA) targeting TROP2 (sh-TROP2) reduced cell proliferation, migration and invasion of OScc cell lines, whereas overexpression of TROP2 increased proliferation, migration and invasion. sh-TROP2 transfection in OScc cell lines inhibited tumor growth in OScc mouse models. Furthermore, TROP2 expression activated the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway in human OScc cells. These results suggest that TROP2 induces cell growth, migration and invasion through activation of the PI3K/Akt signaling pathway in OScc cells.