Epithelial-Mesenchymal Transition during Metastasis of HPV-Negative Pharyngeal Squamous Cell Carcinoma

Evidence that cervical cancer cells cultured as tumorspheres maintain high CD73 expression and increase their protumor characteristics through TGF-β production

Recently, a link between the biological activity of CD73 and tumorigenicity in solid tumors has been proposed. We previously reported that the generation of adenosine (Ado) by the activity of CD73 in cervical cancer (CC) cells induces transforming growth factor-beta 1 (TGF-β1) production to maintain CD73 expression. In the present study, we analyzed the participation of TGF-β1 in CD73 expression and the development of protumoral characteristics in CaSki CC cells cultured as tumorspheres (CaSki-T) and in monolayers (CaSki-M). Compared with those in CaSki-M cells, CD73 expression and Ado generation ability were significantly increased in CaSki-T cells. CaSki-T cells exhibited enrichment in the CSC-like phenotype due to increases in the expression levels of stem cell markers (CD49f, CK17, and P63; OCT4 and SOX2), greater sphere formation efficiency (SFE), and an increase in the percentage of side population (SP) cells. Interestingly, compared with CaSki-M cells, CaSki-T cells produced a greater amount of TGF-β1 and presented a marked protumor phenotype characterized by a significant decrease in the expression of major histocompatibility complex class-I (MHC-I) molecules, an increase in the expression of multidrug resistance protein-I (MRP-I) and vimentin, and an increase in the protein expression levels of Snail-1 and Twist, which was strongly reversed with TGF-β1 inhibition. These results suggest that the presence of TGF-β1-CD73-Ado feedback loop can promote protumoral characteristics in the CC tumor microenvironment.

Suppression of Long Noncoding RNA SNHG1 Inhibits the Development of Hypopharyngeal Squamous Cell Carcinoma via Increasing PARP6 Expression

Purpose

This study aimed to explore the function and molecular mechanism of long noncoding RNA Small Nucleolar RNA Host Gene 1 (SNHG1) in the development of hypopharyngeal squamous cell carcinoma (HSCC).

Methods

Human HSCC cell line FaDu was used in this study. Cell viability and apoptosis were detected using CCK-8 assay and flow cytometry, respectively. Cell migration and invasion were measured by Transwell assay. The expression of PARP6, XRCC6, β-catenin, and EMT-related proteins (E-cadherin and N-cadherin) were determined using western blotting. Moreover, the regulatory relationship between SNHG1 and PARP6 was investigated. Furthermore, the effects of the SNHG1/PARP6 axis on tumorigenicity were explored in vivo.

Results

Suppression of SNHG1 suppressed the viability, migration, and invasion but promoted apoptosis of FaDu cells in vitro (P < 0.01). PARP6 is a target of SNHG1, which was upregulated by SNHG1 knockdown in FaDu cells (P < 0.01). SNHG1 suppression and RARP6 overexpression inhibited FaDu cell proliferation, migration, and invasion (P < 0.05). SNHG1 suppression and RARP6 overexpression also inhibited tumorigenicity of HSCC in vivo. Furthermore, the protein expression of E-cadherin was significantly increased and that of N-cadherin, β-catenin, and XRCC6 was dramatically decreased in HSCC after SNHG1 suppression or/and RARP6 overexpression both in vitro and in vivo (P < 0.01).

Conclusions

SNHG1 silencing inhibits HSCC malignant progression via upregulating PARP6. XRCC6/β-catenin/EMT axis may be a possible downstream mechanism of the SNHG1/PARP6 axis in HSCC. SNHG1/PARP6 can be used as a promising target for the treatment of HSCC.

Differences in Extracellular Vesicle Protein Cargo Are Dependent on Head and Neck Squamous Cell Carcinoma Cell of Origin and Human Papillomavirus Status

To identify potential extracellular vesicle (EV) biomarkers in head and neck squamous cell carcinoma (HNSCC), we evaluated EV protein cargo and whole cell lysates (WCL) from HPV-positive and -negative HNSCC cell lines, as well as normal oral keratinocytes and HPV16-transformed cells. EVs were isolated from serum-depleted, conditioned cell culture media by polyethylene glycol (PEG) precipitation/ultracentrifugation. EV and WCL preparations were analyzed by LC-MS/MS. Candidate proteins detected at significantly higher levels in EV compared with WCL, or compared with EV from normal oral keratinocytes, were identified and confirmed by Wes Simple Western protein analysis. Our findings suggest that these proteins may be potential HNSCC EV markers as proteins that may be (1) selectively included in EV cargo for export from the cell as a strategy for metastasis, tumor cell survival, or modification of tumor microenvironment, or (2) representative of originating cell composition, which may be developed for diagnostic or prognostic use in clinical liquid biopsy applications. This work demonstrates that our method can be used to reliably detect EV proteins from HNSCC, normal keratinocyte, and transformed cell lines. Furthermore, this work has identified HNSCC EV protein candidates for continued evaluation, specifically tenascin-C, HLA-A, E-cadherin, EGFR, EPHA2, and cytokeratin 19.

Precision Medicine Gains Momentum: Novel 3D Models and Stem Cell-Based Approaches in Head and Neck Cancer

Despite the current progress in the development of new concepts of precision medicine for head and neck squamous cell carcinoma (HNSCC), in particular targeted therapies and immune checkpoint inhibition (CPI), overall survival rates have not improved during the last decades. This is, on the one hand, caused by the fact that a significant number of patients presents with late stage disease at the time of diagnosis, on the other hand HNSCC frequently develop therapeutic resistance. Distinct intratumoral and intertumoral heterogeneity is one of the strongest features in HNSCC and has hindered both the identification of specific biomarkers and the establishment of targeted therapies for this disease so far. To date, there is a paucity of reliable preclinical models, particularly those that can predict responses to immune CPI, as these models require an intact tumor microenvironment (TME). The "ideal" preclinical cancer model is supposed to take both the TME as well as tumor heterogeneity into account. Although HNSCC patients are frequently studied in clinical trials, there is a lack of reliable prognostic biomarkers allowing a better stratification of individuals who might benefit from new concepts of targeted or immunotherapeutic strategies. Emerging evidence indicates that cancer stem cells (CSCs) are highly tumorigenic. Through the process of stemness, epithelial cells acquire an invasive phenotype contributing to metastasis and recurrence. Specific markers for CSC such as CD133 and CD44 expression and ALDH activity help to identify CSC in HNSCC. For the majority of patients, allocation of treatment regimens is simply based on histological diagnosis and on tumor location and disease staging (clinical risk assessments) rather than on specific or individual tumor biology. Hence there is an urgent need for tools to stratify HNSCC patients and pave the way for personalized therapeutic options. This work reviews the current literature on novel approaches in implementing three-dimensional (3D) HNSCC in vitro and in vivo tumor models in the clinical daily routine. Stem-cell based assays will be particularly discussed. Those models are highly anticipated to serve as a preclinical prediction platform for the evaluation of stable biomarkers and for therapeutic efficacy testing.

Cancer Stem Cell Markers in Squamous Cell Carcinomas of the Salivary Glands

BACKGROUND

Cancer stem cells (CSC) are cells that exhibit stem cell properties and are pivotal in tumor biology. CSC markers have been described for many tumorous entities. However, to this date, there is no data on CSC markers in respect to squamous cell carcinomas (SCC) of the salivary glands.

METHODS

Histologic samples from patients with salivary gland SCCs were stained for CSC markers (ALDH-1/BMI-1/SOX-2/CD-44/vimentin) and divided into high and low expression subgroups. These were then correlated with tumor and patient characteristics as well as overall survival (OS), disease-specific survival, recurrence-free survival and local control rates (LCR) after 3 and 5 years.

RESULTS

Overall, 31 samples were included. CD-44 and ALDH-1 expression were associated with tumor origin (metastatic/primary disease, p = 0.048 and p = 0.011, respectively). Strong BMI-1 expression was associated with poorer OS (62.9 vs. 27.3%, p = 0.029), strong SOX-2 expression was associated with poorer LCR (62.5 vs. 21.9%, p = 0.007).

CONCLUSION

CD-44 and ALDH-1 may be useful in differentiating between primary SCCs and metastatic disease. BMI-1 and SOX-2 are correlated with poorer prognosis.

An immune-related seven-lncRNA signature for head and neck squamous cell carcinoma

In this study, we developed a long noncoding RNA (lncRNA)‐based prognostic signature for stratification of patients with head a nd neck squamous cell carcinoma (HNSCC). In total, 493 HNSCC samples obtained from the Cancer Genome Atlas database were divided into training and testing cohorts (3:2 ratio). We identified 3913 immune‐related lncRNAs in the HNSCC training cohort by Pearson correlation analysis; only seven were independently associated with overall survival and were used to develop an immune‐related lncRNA prognostic signature (IRLPS) grouping of HNSCC patients into high‐ and low‐IRLPS subgroups. Univariate and multivariate Cox analyses revealed that low‐IRLPS patients had a better prognosis in all the cohorts, which was retained after stratification by sex, grade, and HPV status. Although the TNM stage was also an independent prognostic factor, the IRLPS had a better discriminability with higher AUC at the 3‐ and 5‐year follow‐ups in all cohorts. Low‐IRLPS samples had more immune cell infiltration and were enriched in immune‐related pathways, while high‐ IRLPS samples were enriched in metabolic pathways. A nomogram constructed including age, TNM stage, and IRLPS showed good calibration. Thus, IRLPS improves the prognostic prediction and also distinguishes different tumor microenvironment (TME) in HNSCC patients.

Human Papillomavirus and Cellular Pathways: Hits and Targets

The Human Papillomavirus (HPV) is the causative agent of different kinds of tumors, including cervical cancers, non-melanoma skin cancers, anogenital cancers, and head and neck cancers. Despite the vaccination campaigns implemented over the last decades, we are far from eradicating HPV-driven malignancies. Moreover, the lack of targeted therapies to tackle HPV-related tumors exacerbates this problem. Biomarkers for early detection of the pathology and more tailored therapeutic approaches are needed, and a complete understanding of HPV-driven tumorigenesis is essential to reach this goal. In this review, we overview the molecular pathways implicated in HPV infection and carcinogenesis, emphasizing the potential targets for new therapeutic strategies as well as new biomarkers.

Role of cancer stem cell markers ALDH1, BCL11B, BMI-1, and CD44 in the prognosis of advanced HNSCC

Purpose

Cancer stem cells (CSCs) are held accountable for the progress of head and neck squamous cell carcinoma (HNSCC). In the presented study, the authors evaluated the prognostic value of CSC markers in two particular HNSCC cohorts.

Methods

This two cohort study consisted of 85 patients with advanced stage HNSCC, treated with primary radio(chemo)therapy (pRCT), and 95 patients with HNSCC, treated with surgery and partially adjuvant radio(chemo)therapy. Overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) were assessed. Samples were assessed for the expression of different molecular stem cell markers (ALDH1, BCL11B, BMI‑1, and CD44).

Results

In the pRCT cohort, none of the baseline patient and tumor features exhibited a statistically significant relation with survival in either the cohort or the human papillomavirus (HPV)-stratified subcohorts. High expression of BMI‑1 significantly decreased OS and DFS, while high expression of CD44 decreased all modes of survival. Multivariate analysis showed significant prognostic influence for all tested CSC markers, with high BMI‑1 and CD44 decreasing survival (BMI-1: OS, DFS, DSS; CD44: OS, DFS) and high ALDH1 and BCL11B showing a beneficial effect on survival (ALDH1: OS, DFS; BCL11B: OS, DSS). In the surgical cohort, classical prognosticators such as HPV status, R1 resection, and nodal status in HPV-negative HNSCC played a significant role, but the tested CSC markers showed no significant effect on prognosis.

Conclusion

Although validation in independent cohorts is still needed, testing for CSC markers in patients with advanced or late stage HNSCC might be beneficial, especially if many comorbidities exist or disease is irresectable. The findings might guide the development and earlier use of targeted therapies in the future.

Electronic supplementary material

The online version of this article (10.1007/s00066-020-01653-5) contains supplementary material, which is available to authorized users.

Downregulation of SEMA4C Inhibit Epithelial-Mesenchymal Transition (EMT) and the Invasion and Metastasis of Cervical Cancer Cells via Inhibiting Transforming Growth Factor-beta 1 (TGF-β1)-Induced Hela cells p38 Mitogen-Activated Protein Kinase (MAPK) Activation

BACKGROUND Epithelial-mesenchymal transition (EMT) plays a key role in promoting invasion and metastasis of tumor cells. SEMA4C can regulate the generation of transforming growth factor-beta 1 (TGF-ß1)-induced EMT in cervical cancer. This study investigated the relationship between the regulation of SEMA4C on TGF-ß1-induced p38 mitogen-activated protein kinase (MAPK) activation and invasion and metastasis of cervical cancer. MATERIAL AND METHODS Hela-shSEMA4C cell line was established and the success of transfection was confirmed with fluorescence intensity. Cell experiments were divided into 2 groups. Group 1 was Hela, Hela-shNC, and Hela-shSEMA4C; and Group 2 was Hela, Hela-shNC, Hela-shSEMA4C, Hela+TGF-ß1, Hela-shNC+TGF-ß1, and Hela-shSEMA4C+TGF-ß1. Group 1 was detected for SEMA4C mRNA expression by real-time polymerase chain reaction (RT-PCR), cell viability by Cell Counting Kit-8 (CCK-8), F-actin fluorescence intensity by immunofluorescence, cell migration by scratch test, and cell invasion by invasion test. Group 2 was analyzed for E-cadherin fluorescence intensity by immunofluorescence, human fibronectin (FN) content by enzyme-linked immunosorbent assay (ELISA), and SEMA4C, E-cadherin and p-p38 expressions by Western blot. RESULTS For Group 1, compared with Hela and Hela-shNC subgroups, the SEMA4C mRNA expression, cell viability, F-actin fluorescence intensity, cell migration and invasion ability in the Hela-shSEMA4C subgroup were significantly decreased (P<0.05). For Group 2, compared with Hela and Hela-shNC subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C subgroup were significantly increased (P<0.01), while the FN content, SEMA4C, and p-p38 MAPK expressions were significantly decreased (P<0.01). Compared with Hela-shNC+TGF-ß1 and Hela+TGF-ß1 subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C+TGF-ß1 subgroup were significantly increased (P<0.01), while the FN content, SEMA4C and p-p38 expressions were significantly decreased (P<0.01). CONCLUSIONS Downregulation of SEMA4C can inhibit EMT and the invasion and metastasis of cervical cancer cells via inhibiting TGF-ß1-induced Hela cells p38 MAPK activation.

Feature selection with the Fisher score followed by the Maximal Clique Centrality algorithm can accurately identify the hub genes of hepatocellular carcinoma

This study aimed to select the feature genes of hepatocellular carcinoma (HCC) with the Fisher score algorithm and to identify hub genes with the Maximal Clique Centrality (MCC) algorithm. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to examine the enrichment of terms. Gene set enrichment analysis (GSEA) was used to identify the classes of genes that are overrepresented. Following the construction of a protein-protein interaction network with the feature genes, hub genes were identified with the MCC algorithm. The Kaplan–Meier plotter was utilized to assess the prognosis of patients based on expression of the hub genes. The feature genes were closely associated with cancer and the cell cycle, as revealed by GO, KEGG and GSEA enrichment analyses. Survival analysis showed that the overexpression of the Fisher score–selected hub genes was associated with decreased survival time (P < 0.05). Weighted gene co-expression network analysis (WGCNA), Lasso, ReliefF and random forest were used for comparison with the Fisher score algorithm. The comparison among these approaches showed that the Fisher score algorithm is superior to the Lasso and ReliefF algorithms in terms of hub gene identification and has similar performance to the WGCNA and random forest algorithms. Our results demonstrated that the Fisher score followed by the application of the MCC algorithm can accurately identify hub genes in HCC.