Metastasis Of Cutaneous Squamous Cell Carcinoma Research Articles

TEMPORARY REMOVAL: Limitations of the Commercially Available Gene Expression Test in Predicting Cutaneous Squamous Cell Carcinoma Metastasis and Clinical Outcomes

BackgroundClinical genetic tests are integral to healthcare decision-making. However, the unclear regulatory framework, especially regarding products that evade stringent FDA oversight, may compromise test validity and transparency. ObjectiveTo critically evaluate the DecisionDx® cutaneous squamous cell carcinoma test by Castle Biosciences for its dataset biases, gene panel selection, and reported accuracy metrics, providing insight into broader challenges in the clinical genetic testing landscape. MethodsIndependent analyses of the DecisionDx®-SCC 40-GEP test data from Castle Biosciences were conducted. These included comparisons to clinical genetic testing standards, analysis of prevalence metrics against national cSCC rates, gene ontology of 34 genes for cSCC associations, and evaluation of accuracy metrics. ResultsThe DecisionDx®-SCC met 11 of 44 CDC’s ACCE criteria for clinical genetic testing. Its dataset showed a metastasis prevalence higher than the national average. Out of 34 genes, 15 had known associations with cSCC. Inconsistencies in accuracy metrics presentation were noted, particularly in moderate and high-risk stratifications. ConclusionAnalysis of DecisionDx®-SCC indicates potential biases and ambiguities, exacerbated by differences between FDA and CLIA standards. This highlights the need for systematic validation and a unified regulatory approach, stressing the necessity for precise and dependable genetic testing in patient care.

Cumulative incidence and risk factors for cutaneous squamous cell carcinoma metastases in organ transplant recipients: The Skin Care in Organ Transplant Patients in Europe-International Transplant Skin Cancer Collaborative metastases study, a prospective multicenter study

Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. Of 514 SOTRs who presented with 623 primary cSCCs, metastases developed in 37 with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size > 2cm, clinical ulceration, poor differentiation grade, perineural invasion, and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9%-68.4%). SOTRs have a high risk of cSCC metastases and well-established clinical and histologic risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis.

LB1663 A multi-gene prognostic signature associated with cutaneous squamous cell carcinoma metastasis

LB1663 A multi-gene prognostic signature associated with cutaneous squamous cell carcinoma metastasis

Circ_0068631 sponges miR-139-5p to promote the growth and metastasis of cutaneous squamous cell carcinoma by upregulating HOXB7.

Circular RNAs (circRNAs) are often dysregulated in cancers and closely related to cancer progression, including cutaneous squamous cell carcinoma (CSCC). However, the role and mechanism of circ_0068631 in CSCC progression have not been reported. The expression of circ_0068631, microRNA-139-5p (miR-139-5p), and homeobox B7 (HOXB7) was measured by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, and colony formation assay were used to measure cell proliferation. Cell apoptosis was assessed by flow cytometry. Cell migration was detected by transwell assay. The interaction between miR-139-5p and circ_0068631 or HOXB7 was confirmed by dual-luciferase reporter assay. A xenograft tumor model was established to confirm the function of circ_0068631 in vivo. Circ_0068631 was upregulated in CSCC tissues and cells, and its silencing could inhibit CSCC cell proliferation and metastasis while promoting apoptosis in vitro, as well as restrain CSCC tumor growth in vivo. Circ_0068631 acted as a sponge of miR-139-5p, and miR-139-5p inhibition reversed the repressive effect of circ_0068631 knockdown on CSCC cell progression. Furthermore, HOXB7 was a target of miR-139-5p, and miR-139-5p inhibited the malignant behaviors by downregulating HOXB7 expression in CSCC cells. Further, circ_0068631 sponged miR-139-5p to regulate HOXB7 expression. Circ_0068631 functioned as a novel oncogene in CSCC progression by regulating miR-139-5p/HOXB7 axis, suggesting that circ_0068631 may be a potential target for CSCC treatment. Circ_0068631 was overexpressed in CSCC tissues and cells. Circ_0068631 downregulation suppressed CSCC progression via miR-139-5p. Circ_0068631 regulated HOXB7 via sponging miR-139-5p.

HLA expression as a risk factor for metastases of cutaneous squamous-cell carcinoma in organ- transplant recipients

BackgroundSolid organ-transplant recipients (SOTR) have an increased risk of cutaneous squamous-cell carcinoma (cSCC), metastasis and death from cSCC. In immunocompetent patients with mucosal SCC, downregulation of HLA class I is associated with poor prognosis. Since the degree of HLA expression on tumor cells could play a role in immunogenicity and pathophysiology of cSCC metastasis, we hypothesized that decreased HLA expression is associated with an increased risk of metastasis. MethodsWe compared HLA expression between primary metastasized cSCCs, their metastases, and non-metastasized cSCCs from the same patients. Samples were stained for HLA-A, HLA-B/-C and quantified by calculating the difference in immunoreactivity score (IRS) of the primary cSCC compared with all non-metastasized cSCCs. ResultsThe mean IRS score for HLA-B/C expression was 2.07 point higher in metastasized compared to non-metastasized cSCCs (p = 0.065, 95 % CI −0.18–4.32). 83.3 % of the primary metastasized cSCCs had an IRS score of 4 or higher, compared to 42.9 % in non-metastasized cSCCs. Moderately to poorly differentiated cSCCs had more HLA class I expression compared to well-differentiated cSCCs. ConclusionContrary to immunocompetent patients, HLA-B/C expression tends to be upregulated in metastasized cSCC compared to non-metastasized cSCC in SOTR, suggesting that different tumor escape mechanisms play a role in SOTR compared to immunocompetent patients.

Immune status does not independently influence cutaneous squamous cell carcinoma metastasis and death when stratified by tumor stage: A dual-center retrospective cohort analysis of primary N0 disease

Although immunocompromised patients have a higher risk of developing cutaneous squamous cell carcinomas, it is unknown whether immune status is an independent risk factor for poor outcomes. To compare cutaneous squamous cell carcinoma outcomes in immunocompromised and immunocompetent patients when controlling for T-stage. We performed a retrospective cohort study at 2 tertiary care centers, examining 989 primary tumors from 814 immunocompromised patients (solid organ transplant: 259 [31.7%], chronic lymphocytic leukemia: 113 [13.9%]) and 6608 tumors from 4198 immunocompetent patients. Our primary outcome was the composite of disease-specific death or tumor metastasis ("poor outcomes"). Immunocompromised patients had 50% more high T-stage tumors (ie, Brigham and Women's Hospital stage T2b and T3), than immunocompetent patients (3.3% vs 4.9%, respectively; P<.001). Significant predictors of poor outcomes included tumor stage (sub hazards ratio [SHR], 14.8 for high T-stage tumors; 95% confidence interval [CI], 8.0-27.6; P<.001) and male sex (SHR, 2.3; 95% CI, 1.4-3.8; P=.002). Immune status was not a significant predictor (SHR, 1.04; 95% CI, 0.69-1.6; P=.85). This study is retrospective. Although immunocompromised patients had 50% more high T-stage tumors than immunocompetent patients, immunocompromised patients had a similar chance of metastasis and disease-specific death when adjusting for T-stage in our cohort of primary tumors.

Circular RNA circFADS2 inhibits the progression of cutaneous squamous cell carcinoma by regulating miR-766-3p/HOXA9 axis.

Mounting evidence indicates that circular RNAs (circRNAs) play vital roles in human diseases, especially in cancers. However, the biological functions and underlying mechanism of circRNA fatty acid desaturase 2 (circFADS2) in cutaneous squamous cell carcinoma (CSCC) have not been reported. The expression levels of circFADS2, microRNA-766-3p (miR-766-3p) and homeobox A9 (HOXA9) were determined by quantitative real-time PCR (qRT-PCR). Flow cytometry analysis was used to determine cell cycle distribution. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) and colony formation assays. Wound healing and transwell assays were used to assess cell migration and invasion abilities. Glycolysis was examined via the measurement of extracellular acidification rate (ECAR). All protein levels were detected by western blot assay. The interaction between miR-766-3p and circFADS2 or HOXA9 was predicted by bioinformatics software and confirmed by dual-luciferase reporter, RNA pull-down, and RNA Immunoprecipitation (RIP) assays. The mouse xenograft model was established to investigate the role of circFADS2 in vivo. CircFADS2 was downregulated in CSCC tissues and cells. CircFADS2 overexpression inhibited CSCC cell proliferation, metastasis and glycolysis. Moreover, miR-766-3p was able to directly bind to circFADS2, and circFADS2 played an anti-cancer role in CSCC by downregulating miR-766-3p. In addition, HOXA9 was a direct target of miR-766-3p, and miR-766-3p inhibition suppressed CSCC cell proliferation, metastasis and glycolysis by upregulating HOXA9. Furthermore, circFADS2 acted as a sponge of miR-766-3p to regulate HOXA9 expression. Besides, circFADS2 suppressed tumor growth in vivo. CircFADS2 suppressed CSCC progression by regulating miR-766-3p/HOXA9 axis, which might provide a promising therapeutic target for CSCC.

Downregulation of lncRNA NEAT1 inhibits the proliferation of human cutaneous squamous cell carcinoma in vivo and in vitro.

BackgroundThe incidence of cutaneous squamous cell carcinoma (CSCC), a malignant tumor that threatens human life, is increasing every year, and yet its pathogenesis is still unclear. This study found that long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) was abnormally expressed in CSCC. However, the biochemical mechanisms of lncRNA NEAT1 in carcinogenesis and the development of cancer remain unclear.MethodsFluorescence quantitative polymerase chain reaction (qPCR) was conducted to determine lncRNA NEAT1 expression in CSCC and paracarcinoma tissues and investigate the correlation between NEAT1 levels and patients’ clinicopathological features. The invasion, proliferation, and migration of CSCC cells were measured using colony formation, Cell Counting Kit-8, and Transwell assays. Western blot assay was conducted to test whether NEAT1 knockdown affected invasion and migration-related proteins. In addition, a nude mouse subcutaneous tumorigenesis experiment was performed to determine whether the knockdown of NEAT1 affected the proliferation ability of CSCC cells.ResultsChanges in lncRNA NEAT1 expression in CSCC tissues were correlated with the degree of lymph node metastasis and the tumor, regional lymph nodes, and distant metastasis (TNM) grade of patients. The downregulation of NEAT1 lncRNA significantly impeded cell invasion, proliferation, and migration in CSCC. Through lncRNA NEAT1 knockdown, significant reductions in metalloproteinase-2, metalloproteinase-9, N-cadherin, and vimentin expression were observed, and the level of E-cadherin increased. In vivo experiments in nude mice revealed that knockdown of lncRNA NEAT1 greatly inhibited cell proliferation in CSCC.ConclusionsIn CSCC tissues, NEAT1 lncRNA was expressed at high levels and correlated with lymph node metastasis and TNM stage. The knockdown of NEAT1 lncRNA could significantly impede CSCC proliferation, metastasis, and invasion. Additionally, by measuring the expression level of lncRNA NEAT1, we may be able to detect the clinical and pathological characteristics of CSCC.

The CD200-CD200R Axis Promotes Squamous Cell Carcinoma Metastasis via Regulation of Cathepsin K.

The CD200-CD200R immunoregulatory signaling axis plays an etiologic role in the survival and spread of numerous cancers, primarily through suppression of antitumor immune surveillance. Our previous work outlined a prometastatic role for the CD200-CD200R axis in cutaneous squamous cell carcinoma (cSCC) that is independent of direct T-cell suppression but modulates the function of infiltrating myeloid cells. To identify effectors of the CD200-CD200R axis important for cSCC metastasis, we conducted RNA sequencing profiling of infiltrating CD11B+Cd200R+ cells isolated from CD200+ versus CD200-null cSCCs and identified the cysteine protease cathepsin K (Ctsk) to be highly upregulated in CD200+ cSCCs. CD11B+Cd200R+ cells expressed phenotypic markers associated with myeloid-derived suppressor cell-like cells and tumor-associated macrophages and were the primary source of Ctsk expression in cSCC. A Cd200R+ myeloid cell-cSCC coculture system showed that induction of Ctsk was dependent on engagement of the CD200-CD200R axis, indicating that Ctsk is a target gene of this pathway in the cSCC tumor microenvironment. Inhibition of Ctsk, but not matrix metalloproteinases, significantly blocked cSCC cell migration in vitro. Finally, targeted CD200 disruption in tumor cells and Ctsk pharmacologic inhibition significantly reduced cSCC metastasis in vivo. Collectively, these findings support the conclusion that CD200 stimulates cSCC invasion and metastasis via induction of Ctsk in CD200R+ infiltrating myeloid cells. SIGNIFICANCE: These findings highlight the relationship between CD200-CD200R and cathepsin K in cutaneous squamous cell carcinoma metastasis and suggest that either of these components may serve as a viable therapeutic target in this disease.

MicroRNA-21 Contributes to Cutaneous Squamous Cell Carcinoma Progression via Mediating TIMP3/PI3K/AKT Signaling Axis.

BackgroundThough the therapeutic potentials of microRNAs (miRNAs) are extensively explored in cutaneous squamous cell carcinoma (CSCC), the concrete function of miR-21 in this disorder has not been thoroughly comprehended. Therein, this work is launched to clarify the miR-21-pivoted mechanism in CSCC from the perspective of tissue inhibitor of metalloproteinases-3 (TIMP3) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway.MethodsMicroarray-based analysis was utilized to screen out miR-21 with the most up-regulated expression in CSCC tissues. The relation between miR-21 and TIMP3 expression in tissues, and the overall survival of CSCC patients was evaluated. Loss-of-function assays were performed in cells to explore the independent and combined functions of miR-21 and TIMP3 in CSCC cell progression. Mice were injected with miR-21 inhibitor or TIMP3 si for identifying their roles in tumor formation and liver metastasis. The mechanism among miR-21, TIMP3 and PI3K/AKT pathway was interpreted.ResultsMiR-21 was up-regulated while TIMP3 was down-regulated in CSCC tissues, which were connected with unsatisfactory survival of patients. Down-regulating miR-21 inhibited CSCC cell progression and retarded CSCC tumor formation and metastasis in mice. Silencing of TIMP3 reversed the effects of miR-21 down-regulation on CSCC progression. Besides, down-regulating miR-21 inhibited PI3K/AKT pathway activation in CSCC cells via mediating TIMP3.ConclusionIt is elucidated that miR-21 depletion impedes CSCC cell invasion and metastasis via enhancing TIMP3 and suppressing PI3K/AKT pathway activation.

Risk Factors Party Together: The Role of Perineural Invasion and Desmoplasia in Cutaneous Squamous Cell Carcinoma Prognosis

In the current issue, Haug etal. 2020 report on the prognostic impact of perineural invasion (PNI) and desmoplasia on cutaneous squamous cell carcinoma (CSCC) recurrence and metastasis. They find that PNI occurs exclusively in desmoplastic CSCC, and desmoplasia is independently associated with CSCC recurrence and metastasis after adjusting for well-established CSCC risk factors. Future studies should assess the contribution of desmoplasia in CSCC prognosis.

The scalp is a high-risk site for cutaneous squamous cell carcinoma metastasis

To the Editor: The ear and lip have historically been considered anatomic sites at high risk for metastasis of cutaneous squamous cell carcinoma (cSCC). Although the Eighth Edition of the American Joint Committee on Cancer Staging (AJCC) for cSCC does not segregate risk by anatomic location,1 current National Comprehensive Cancer Network (NCCN) guidelines include the lip and ear among “high-risk regions” and the scalp among “moderate-risk regions,”2 implying a lower metastatic risk for cSCC on the scalp vs on the lip or ear.

MiR-506 contributes to malignancy of cutaneous squamous cell carcinoma via targeting of P65 and LAMC1

ABSTRACT Previous research has shown that microRNA 506 (miR-506) functions as an essential modulator in the development of many biological reactions, including multiple cancers. However, its involvement in cutaneous squamous cell carcinoma (CSCC) has been rarely reported. In the present work, we investigated the molecular mechanism and function of miR-506 in the regulation of CSCC cell viability and metastasis (migration and invasion). We observed that miR-506 expression was upregulated in both CSCC tissues and cell lines, and that decreased miR-506 expression led to repressed tumorigenesis in CSCC cells. Furthermore, flow cytometry revealed that the depletion of miR-506 resulted in decreased proliferation and increased apoptotic levels in CSCC cells. Meanwhile, it was found that miR-506 decreased CSCC cell migration and invasion in vitro. The dual-luciferase reporter assay also revealed that miR-506 targets the 3′-UTRs of p65 and Laminin C1 (LAMC1) for silencing. Silencing of p65 expression counteracted the pro-apoptotic influence of miR-506 depletion in CSCC cells, while inhibition of LAMC1 expression restored the migration and invasion properties of the CSCC cells. Therefore, the results provide evidence for the need to probe the biological and molecular mechanisms behind the development and progression of CSCC and may lead to novel treatment CSCC strategies.

Mutational Patterns in Metastatic Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma from the head and neck typically metastasize to the lymph nodes of the neck and parotid glands. When a primary is not identified, they are difficult to distinguish from metastases of mucosal origin and primary salivary gland squamous cell carcinoma. UV radiation causes a mutation pattern that predominantly features cytosine to thymine transitions at dipyrimidine sites and has been associated with cutaneous squamous cell carcinoma. In this study, we used whole genome sequencing data from 15 cutaneous squamous cell carcinoma metastases and show that a UV mutation signature is pervasive across the cohort and distinct from mucosal squamous cell carcinoma. The mutational burden was exceptionally high and concentrated in some regions of the genome, especially insulator elements (mean 162 mutations/megabase). We therefore evaluated the likely impact of UV-induced mutations on the dipyrimidine-rich binding site of the main human insulator protein, CCCTC-binding factor, and the possible implications on CCCTC-binding factor function and the spatial organization of the genome. Our findings suggest that mutation signature analysis may be useful in determining the origin of metastases in the neck and the parotid gland. Furthermore, UV-induced DNA damage to insulator binding sites may play a role in the carcinogenesis and progression of cutaneous squamous cell carcinoma.

Clinical and Incidental Perineural Invasion of Cutaneous Squamous Cell Carcinoma

ImportancePerineural invasion (PNI) in cutaneous squamous cell carcinoma (CSCC) has been associated with an increased risk of poor outcomes. Patients with PNI may present with clinical symptoms and/or radiologic evidence of PNI (clinical PNI [CPNI]), yet most patients are asymptomatic and PNI is often found on histologic examination (incidental PNI [IPNI]). Evidence-based estimates of the risks of disease-related outcomes comparing IPNI and CPNI are limited in the dermatology literature.ObjectivesTo review and synthesize outcomes data for patients with CSCC and CPNI or IPNI.Data SourcesA systematic review was conducted in MEDLINE and EMBASE for English-language articles published since inception to November 11, 2016.Study SelectionAll studies that reported a disease-related outcome (local recurrence, nodal metastasis, distant metastasis, or disease-specific death) of CSCCs with CPNI and IPNI were included.Data Extraction and SynthesisArticles were screened for eligibility, and any possible discrepancies in this screening were resolved. Data extracted included study characteristics, tumor characteristics, treatments performed, and disease-related outcomes. Overall risks of disease-related outcomes were generated by pooling patients from eligible studies. χ2 Statistics and Fisher exact tests were used to evaluate differences in disease-related outcomes.Main Outcomes and MeasuresRisks of disease-related outcomes and 5-year recurrence-free, disease-specific, and overall survival.ResultsA total of 12 studies containing 241 patients with CPNI and 381 patients with IPNI were included in the systematic review and analysis. The overall risks of local recurrence and disease-specific death were significantly higher in patients with CSCC and CPNI compared with those with CSCC and IPNI (local recurrence, 37% vs 17%; P < .001; disease-specific death, 27% vs 6%; P < .001). The risks of nodal metastasis and distant metastasis did not differ significantly by PNI classification. Patients with CSCC and CPNI had poorer mean 5-year recurrence-free survival and disease-specific survival compared with patients with IPNI (recurrence-free survival, 61% vs 76%; P = .009; disease-specific survival, 70% vs 88%; P = .002).Conclusions and RelevancePatients with CSCC and CPNI are at an increased risk of local recurrence and disease-specific death compared with patients with CSCC and IPNI and have a 30% risk of death. Patients with PNI may benefit from increased long-term surveillance. Further studies are needed to establish standardized guidelines on follow-up and dermatologic surveillance in this high-risk patient population.

Epidermal growth factor receptor expression is associated with poor outcome in cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans after basal cell carcinoma, and its incidence is dramatically rising. CSCC is rarely problematic, but given its high frequency, the absolute number of complicated cases is also high. It is necessary to identify molecular markers in order to recognize those CSCCs with poor prognosis. There is controversy concerning the role of epidermal growth factor receptor (EGFR) as a marker of prognosis in CSCC. In addition, EGFR-targeted therapies have emerged in recent years and a better understanding of the role of EGFR in CSCC may be of help for some patients in predicting prognosis and guiding curative management. To evaluate the role of EGFR as a prognostic factor in CSCC. We evaluated clinical and histopathological features, including events of poor clinical evolution, in a series of 94 cases of CSCC. We also analysed EGFR expression by immunohistochemistry, fluorescent in situ hybridization and quantitative polymerase chain reaction. We detected EGFR in 85 cases (90%), with overexpression in 33 cases (35%), and aberrant EGFR expression in the cytoplasm in 50 cases (53%). EGFR overexpression in the primary tumours was associated with lymph node progression, tumour-nodes-metastasis stage progression and proliferation (Ki-67 staining) in CSCC. EGFR overexpression and poor grade of differentiation were the strongest independent variables defining lymph node metastasis and progression in CSCC in a logistic regression model. We demonstrate that EGFR overexpression has prognostic implications associated with lymph node metastasis and progression in CSCC.

Staging cutaneous squamous cell carcinoma metastases to the parotid gland.

The staging of cutaneous squamous cell cancers (cSCC) was revised by the American Joint Committee on Cancer in 2010 to incorporate known prognostic factors and expand the N (node) category. The purpose of this study was to validate this staging system using a North American cohort, and to compare it to the O'Brien P (Parotid) and N staging system. An exhaustive collaborative database search was performed for all patients with cSCC metastasis to the parotid gland treated at three major Canadian tertiary referral centers from December 1999 to March 2015. The data collected for each patient included overall survival; disease-free survival; tumor, node, and metastasis) staging; and postoperative radiation status. Post-hoc analysis was completed to discern the strongest prognostic factors of survival as they relate to the abovementioned staging systems. Of 136 patients identified, 80% had a documented history of previously treated head and neck cSCC an average of 27 months prior to presentation. Average size of the parotid lesion at recurrence was 4.5 cm. Ninety-six percent of patients underwent surgical resection of the parotid metastasis. Five-year overall and disease-free survival is 79% and 55%, respectively. Only cSCC staging and cSCC-N category had statistically significant differences between groups. cSCC staging had the largest percentage of variation in overall survival explained. Patients with cSCC metastasis to the parotid gland proved to have a moderate survival rate, despite presenting with advanced disease. cSCC staging in the setting of parotid metastasis, despite its limitations, currently offers the most predictive staging system available. 4. Laryngoscope, 127:2063-2069, 2017.

High mobility group box 1 regulates tumor metastasis in cutaneous squamous cell carcinoma via the PI3K/AKT and MAPK signaling pathways.

The present study examined the mechanisms of high mobility group box 1 (HMGB1)-induced cell migration in human cutaneous squamous cell carcinoma (CSCC) SCC13 cells. Western blotting, a chemotaxis assay and ELISA were performed to analyze HMGB1 level in SCC13 cells and its ability to regulate tumor metastasis. The results demonstrated a significantly higher level of HMGB1 in the SCC13 cell supernatant compared with the human epidermoid carcinoma A431 cell supernatant. Administration of HMGB1 to the SCC13 cells caused cell migration, which occurred in a time- and dose-dependent manner. Moreover, HMGB1 significantly activated the phosphosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways by an increased level of phosphorylation in p85PI3K, AKT, p38 and p42/44 MAPK. Taken together, these data suggest that HMGB1 regulates tumor metastasis in CSCC via the PI3K/AKT and MAPK signaling pathways.

Role of miR-148a in cutaneous squamous cell carcinoma by repression of MAPK pathway

Dysregulation of miRNAs is a common feature in human cancers, but there are lack of studies on roles of miRNAs in cutaneous squamous cell carcinoma (CSCC). miR-148a, a member of the miR-148/152 family, has been found to be downregulated in different types of cancer and its role in CSCC remains unknown. The study was aimed to investigate the expression and cellular function of miR-148a in CSCC. We found that miR-148a was underexpressed in CSCC tissues and cell lines. MAP3K2, MAP3K4 and MAP3K9 were predicted as the target genes of miR-148a and the latter two genes were verified as the target genes of miR-148a in CSCC cells. Importantly, we demonstrated that the overexpression of miR-148a significantly inhibited CSCC cell proliferation and metastasis via down-regulation of MAP3K9 and MAP3K4 expression. MAP3K4 and MAP3K9 were negatively associated with the expression of miR-148a in CSCC tissues. Our results suggested indicated that miR-148a acts as a tumor suppressor of CSCC via inhibiting MAPK pathway. These results may provide a promising alterative strategy for CSCC therapy.

MiR-20a inhibits cutaneous squamous cell carcinoma metastasis and proliferation by directly targeting LIMK1

Background MicroRNA-20a (miR-20a) plays a key role in tumorigenesis and progression. But its function is reverse in different kinds of malignant tumor, and its role and mechanism in cutaneous squamous cell carcinoma (CSCC) remains unclear. Object To determine the miR-20a’s roles in CSCC and confirm whether LIMK1 is a direct target gene of miR-20a. Methods First miR-20a and LIMK1 expression levels were detected in six pairs of CSCC tissues and corresponding normal skin by qRT-PCR. Then MTT assays and colony formation assays were performed to evaluate the impact of miR-20a on cell proliferation. In addition, scratch migration assays and transwell invasion assays were performed to check miR-20a’s effect on cell metastasis. Since LIMK1 (LIM kinase-1) was predicted as a target gene of miR-20a, the changes of LIMK1 protein and mRNA were measured by western blot and qRT-RCR methods after miR-20a overexpression. Moreover the dual reporter gene assay was performed to confirm whether LIMK1 is a direct target gene of miR-20a. Finally LIMK1 mRNA and miR-20a in other 30 cases of CSCC pathological specimens were determined and a correlation analysis was evaluated. Results The miR-20a significantly low-expressed in CSCC tissues compared with that in matched normal tissues while LIMK1 has a relative higher expression. MiR-20a inhibited A431 and SCL-1 proliferation and metastasis. Both of LIMK1 protein and mRNA levels were downregulated after miR-20a overexpression. The dual reporter gene assays revealed that LIMK1 is a direct target gene of miR-20a. Furthermore, qRT-PCR results of LIMK1 mRNA and miR-20a in 30 cases of CSCC pathological specimens showed miR-20a is inversely correlated with LIMK1 expression. Conclusion Our study demonstrated that miR-20a is involved in the tumor inhibition of CSCC by directly targeting LIMK1 gene. This finding provides potential novel strategies for therapeutic interventions of CSCC.