Hippo pathway and tumoral FOXP3 expression correlate with tumor growth in squamous cell carcinoma of the lung

Deciphering the role of Hippo pathway in lung cancer

Hippo pathway has been initially recognized as a regulatory mechanism for modulation of organ size in fruitfly. Subsequently, its involvement in the regulation of homeostasis and tumorigenesis has been identified. This pathway contains some tumor suppressor genes such as hippo (hpo) and warts (wts), as well as a number of oncogenic ones such as yorkie (yki). Recent studies have shown participation of Hippo pathway in the lung carcinogenesis. This pathway can affect lung cancer via different mechanisms. The interaction between some miRNAs and Hippo pathway is a possible mechanism for carcinogenic processes. Moreover, some other types of non-coding RNAs including PVT1, SFTA1P, NSCLCAT1 and circ_0067741 are implicated in this process. Besides, anti-cancer effects of gallic acid, icotinib hydrochloride, curcumin, ginsenoside Rg3, cryptotanshinone, nitidine chloride, cucurbitacin E, erlotinib, verteporfin, sophoridine, cisplatin and verteporfin in lung cancer are mediated through modulation of Hippo pathway. Here, we summarize the results of recent studies that investigated the role of Hippo signaling in the progression of lung cancer, the impact of non-coding RNAs on this pathway and the effects of anti-cancer agents on Hippo signaling in the context of lung cancer.

Comprehensive analysis reveals CCDC60 as a potential biomarker correlated with prognosis and immune infiltration of head and neck squamous cell carcinoma

Background

Coiled-coil domain containing 60 (CCDC60) is a member of the CCDC family, which participates in the progression of many types of cancer. However, the prognostic value of CCDC60 in head and neck squamous cell carcinoma (HNSC) and its function in tumor immunity remain unclear.

Methods

CCDC60 expression and its prognostic potential in HNSC were evaluated by bioinformatics approaches, which was validated in human HNSC samples. Genetic alteration analysis of CCDC60 and the underlying biological function of CCDC60 related co-expressed genes in HNSC were analyzed. The impact of CCDC60 on the regulation of immune infiltration in HNSC was comprehensively investigated. In vitro, a series of functional assays on CCDC60 were performed in HNSC cells.

Results

Our study has indicated that compared with the adjacent normal tissues, CCDC60 expression was considerably downregulated in HNSC tissues. High CCDC60 expression was connected with favorable outcome of HNSC patients, and its prognostic significance was examined by distinct clinical characteristics. We identified the CCDC60-related co-expression genes, which were mainly enriched in the NOD-like receptor signaling pathway associated with the inhibition of tumor growth, leading to a better prognosis of HNSC patients. In vitro, CCDC60 overexpression significantly inhibited the growth, migration and invasiveness but regulated cell cycle progression, and promoted cell adhesion of Fadu and Cal27 cells. Additionally, high CCDC60 expression had strong connections with the infiltrating levels of immune cells, immune marker sets, immunomodulators and chemokines in HNSC, suggesting that targeting CCDC60 could be a promising strategy to enhance the efficacy of immunotherapy for HNSC patients.

Conclusion

Tumor suppressor CCDC60 may be identified as a prognostic and immune-related indicator in HNSC, which had the potential functions in regulating the immune infiltration of HNSC and improving the response to immunotherapy for HNSC patients.

The role of FOXP3 in non-small cell lung cancer and its therapeutic potentials

Although in the last few decades we have witnessed the rapid development of treatments for non-small cell lung cancer (NSCLC), it still remains the leading cause of cancer-related death. Increasing efforts have been devoted to exploring potential biomarkers and molecular targets for NSCLC. Foxp3, a transcription factor that was discovered as a master regulator of regulatory T cells (Tregs), has been found to express abnormally in tumoral cells including lung cancer cells. In recent years, increasing evidence have surfaced, revealing the carcinogenic effect of FOXP3 in lung cancer. In this review, we analyzed and summarized the function of FOXP3, its regulation and therapeutic potentials in NSCLC, with a hope to facilitate the development of novel treatments for NSCLC.

ERAP2 Is Associated With Immune Infiltration and Predicts Favorable Prognosis in SqCLC

Background

Immunotherapy has been proven effective among several human cancer types, including Squamous cell lung carcinoma (SqCLC). ERAP2 plays a pivotal role in peptide trimming of many immunological processes. However, the prognostic role of ERAP2 and its relationship with immune cell infiltration in SqCLC remains unclear.

Methods

The differential expression of ERAP2 was identified via GEO and TCGA databases. We calculated the impact of ERAP2 on clinical prognosis using the Kaplan-Meier plotter. TIMER was applied to evaluate the abundance of immune cells infiltration and immune markers. SqCLC tissue microarrays containing 190 patients were constructed, and we performed immunohistochemical staining for ERAP2, CD8, CD47, CD68, and PD-L1 to validate our findings in public data.

Results

In the GEO SqCLC database, ERAP2 was upregulated in patients with better survival (p=0.001). ERAP2 expression in SqCLC was significantly lower than that of matched normal samples (p<0.05) based on TCGA SqCLC data. Higher expression of ERAP2 was significantly associated with better survival in SqCLC patients from TCGA (p=0.007), KM-plotter (p=0.017), and our tissue microarrays (TMAs) (p=0.026). In univariate and multivariate Cox analysis of SqCLC TMAs, high ERAP2 expression was identified as an independent protective factor for SqCLC patients (Univariate Cox, HR=0.659, range 0.454-0.956, p<0.05. Multivariate Cox, HR=0.578, range 0.385-0.866, p<0.05). In TIMER, ERAP2 was positively correlated with several immune markers (CD274, p=1.27E-04; CD68, p=5.88E-08) and immune infiltrating cells (CD8⁺ T cell, p=4.09E-03; NK cell, p=1.00E-04). In our cohort, ERAP2 was significantly correlated with CD8⁺ tumor-infiltrating lymphocytes (TILs) (p=0.0029), and patients with higher ERAP2 expression had a higher percentage of PD-L1 positive patients (p=0.049) and a higher CD8⁺ TILs level (p=0.036).

Conclusions

For the first time, our study demonstrates that higher expression of ERAP2 is tightly associated with the immuno-supportive microenvironment and can predict a favorable prognosis in SqCLC. Meanwhile, ERAP2 may be a promising immunotherapeutic target for patients with SqCLC.

High levels of Tim-3+Foxp3+Treg cells in the tumor microenvironment is a prognostic indicator of poor survival of diffuse large B cell lymphoma patients

Foxp3⁺Treg cells display phenotypic and functional heterogeneity, which express high levels of T cell immunoglobulin and mucin-domain containing-3 (Tim-3) in the tumor microenvironment (TME) of colorectal and lung cancer. High abundance of Tim-3⁺Foxp3⁺Treg (TFT) cells are associated with poor prognosis in these patients. However, the expression patterns and roles of TFT cells in TME of diffuse large B cell lymphoma (DLBCL) remain to be established. Double immunofluorescence and flow cytometry analyses were employed to investigate TFT cell enrichment in paraffin-embedded fresh tumor tissues from patients with DLBCL. Spearman's or Pearson's correlation and Kaplan-Meier survival analyses were further applied to decide the prognostic value of TFT cell levels in DLBCL. The IL-10-secreting function of TFT cells in vitro was examined via flow cytometry and ELISA. Our results showed for the first time that TFT cells are highly enriched in TME of DLBCL patients and associated with predictions of poor prognoses. TFT cell-induced secretion of IL-10 in the TME was suppressed by an anti-Tim-3 antibody in vitro. In conclusion, high abundance of TFT cells in the TME is predictive of poor outcomes of DLBCL. TFT cells promote DLBCL development partly by secreting IL-10 in the TME. Anti-Tim-3 antibodies (that block IL-10 secretion) may present an effective therapeutic agent for DLBCL.

The role of Hippo-YAP signaling in squamous cell carcinomas

The Hippo‐YAP pathway regulates organ size, tissue homeostasis, and tumorigenesis in mammals. In response to cell density, external mechanical pressure, and/or other stimuli, the Hippo core complex controls the translocation of YAP1/TAZ proteins to the nucleus and thereby regulates cell growth. Abnormal upregulation or nuclear localization of YAP1/TAZ occurs in many human malignancies and promotes their formation, progression, and metastasis. A key example is squamous cell carcinoma (SCC) genesis. Many risk factors and crucial signals associated with SCC development in various tissues accelerate YAP1/TAZ accumulation, and mice possessing constitutively activated YAP1/TAZ show immediate carcinoma in situ (CIS) formation in these tissues. Because CIS onset is so rapid in these mutants, we propose that many SCCs initiate and progress when YAP1 activity is sustained and exceeds a certain oncogenic threshold. In this review, we summarize the latest findings on the roles of YAP1/TAZ in several types of SCCs. We also discuss whether targeting aberrant YAP1/TAZ activation might be a promising strategy for SCC treatment.