Genome-wide methylation and transcriptome analysis in penile carcinoma: uncovering new molecular markers

Multiomics data identifies RSPO2 as a prognostic biomarker in human tumors associated with pan-cancer

RSPO2 protein may provide valuable insights into the mechanism underlying various types of tumorigenesis. The role of RSPO2 in pan-cancer has not been reported so far. Therefore, this study aimed to provide a comprehensive analysis of RSPO2 from a pan-cancer perspective employing multiomics data. The expression profile and function of RSPO2 across different tumors were investigated using various web-based tools UALCAN, GEPIA, TIMER, Human Protein Atlas, cBioPortal, TISIDB, STRING, and Metascape to interpret the expression profile, promoter methylation status, genomic alterations, survival analysis, protein-protein interaction, correlation with immune cell subtypes, tumor immune microenvironment and enrichment analysis. Comprehensive pan-cancer analysis indicated that RSPO2 was significantly downregulated in eleven and upregulated in five tumor types compared to normal tissues, validation results further suggest RSPO2 was downregulated in most of the tumors. The protein level expression of RSPO2 was mostly low in malignant tissues. We found that RSPO2 was significantly related to individual pathological stages in BLCA, COAD, LUAD and LUSC. Prognostic analysis indicates that the high RSPO2 expression was significantly correlated with the poor prognosis in BRCA, KICH, KIRP, READ, and UCES. Furthermore, RSPO2 is frequently amplified, exhibits hypermethylated promoter in most cancers, and is associated with immune subtypes, molecular subtypes and immune cell infiltration. Finally, enrichment analysis showed that RSPO2 is involved in the regulation of the canonical Wnt pathway and neuronal development. The overall comprehensive pan-cancer analysis affirms that RSPO2 could be a promising diagnostic and prognostic biomarker and latent therapy target in the future.

Human Papillomavirus Infection in Penile Cancer: Multidimensional Mechanisms and Vaccine Strategies

Penile cancer (PC) is a rare male malignant tumor, with early lymph node metastasis and poor prognosis. Human papillomavirus (HPV) plays a key role in the carcinogenesis of PC. This review aims to summarize the association between HPV infection and PC in terms of virus-host genome integration patterns (the disrupted regions in the HPV and PC genome), genetic alterations, and epigenetic regulation (methylation and microRNA modification) occurring in HPV and PC DNA, as well as tumor immune microenvironment reprogramming. In addition, the potential of HPV vaccination strategies for PC prevention and treatment is discussed. Understanding of the HPV-related multidimensional mechanisms and the application of HPV vaccines will promote rational and novel management of PC.

The role of Her-2 in penile squamous cell carcinoma progression and cisplatin chemoresistance and potential for antibody-drug conjugate-based therapy

BACKGROUND

Cisplatin-based chemotherapy has been the first choice for advanced penile squamous cell carcinoma (PSCC) in the last decade, but its utility is limited by the low response rate, systemic toxicity, and chemoresistance, which contribute to a poor prognosis. There is no standard second-line therapy for advanced PSCC. Human epidermal growth factor receptor 2 (Her-2)-targeted antibody-drug conjugates (ADCs) are novel low-toxicity agents which have greatly improved clinical outcomes for several advanced cancers. We aimed to explore the expression pattern, clinical significance, and oncogenic roles of Her-2 and the therapeutic potential of Her-2-targeted ADCs in PSCC.

METHODS

Her-2 immunohistochemistry was performed for the largest single-centre PSCC cohort to date (367 patients). PSCC cell lines, cisplatin-resistant cell lines, subcutaneous xenograft, and footpad metastatic models were used to investigate the biological roles of Her-2 in PSCC progression. Cytotoxicity, apoptosis assays, and western blotting investigated the mechanism of Her-2 induced cisplatin-chemoresistance. The efficacy of Disitamab Vedotin (RC48), a Her-2-targeted ADC, was evaluated in PSCC.

RESULTS

Her-2 was identified as an adverse prognostic indicator associated with advanced Tumor-Node-Metastasis (TNM) stages and poor survival with an immunohistochemical expression rate of approximately 47.7% (1+, 23.2%; 2+, 18.0%; 3+, 6.5%) in PSCC. Her-2 promotes cell proliferation, migration, invasion, tumour progression, and cisplatin resistance in PSCC. Mechanistically, Her-2 inhibits cisplatin-induced cell apoptosis by the activation of Akt phosphorylation at Ser473 and disrupts the balance between proapoptotic and antiapoptotic proteins. Meanwhile, cisplatin-resistant PSCC cells present aggressive oncogenic abilities and Her-2 upregulation. More importantly, RC48 displayed remarkable antitumor activities in both Her2-positive and cisplatin-resistant PSCC tumours.

CONCLUSION

Our study suggests that Her-2 is an available therapeutic biomarker for PSCC. Her-2-targeted ADC might have the potential to improve clinical outcomes in high-risk Her-2-positive advanced PSCC patients and provide precious second-line clinical choice for appropriate cisplatin-based chemoresistance patients.

An Assessment of the Penile Squamous Cell Carcinoma Surfaceome for Biomarker and Therapeutic Target Discovery

Penile squamous cell carcinoma (PSCC) is a rare malignancy in most parts of the world and the underlying mechanisms of this disease have not been fully investigated. About 30-50% of cases are associated with high-risk human papillomavirus (HPV) infection, which may have prognostic value. When PSCC becomes resistant to upfront therapies there are limited options, thus further research is needed in this venue. The extracellular domain-facing protein profile on the cell surface (i.e., the surfaceome) is a key area for biomarker and drug target discovery. This research employs computational methods combined with cell line translatomic (n = 5) and RNA-seq transcriptomic data from patient-derived tumors (n = 18) to characterize the PSCC surfaceome, evaluate the composition dependency on HPV infection, and explore the prognostic impact of identified surfaceome candidates. Immunohistochemistry (IHC) was used to validate the localization of select surfaceome markers. This analysis characterized a diverse surfaceome within patient tumors with 25% and 18% of the surfaceome represented by the functional classes of receptors and transporters, respectively. Significant differences in protein classes were noted by HPV status, with the most change being seen in transporter proteins (25%). IHC confirmed the robust surface expression of select surfaceome targets in the top 85% of expression and a superfamily immunoglobulin protein called BSG/CD147 was prognostic of survival. This study provides the first description of the PSCC surfaceome and its relation to HPV infection and sets a foundation for novel biomarker and drug target discovery in this rare cancer.

Prognostic Markers and Trials in Penile Cancer

New tumor biomarkers open the potential for designing personalized therapy for penile squamous cell carcinoma. Despite the initial promising results of some biomarkers, controversy remains due to contradictory studies. Further robust research work is required before incorporating biomarkers in the personalized management of penile cancer. This narrative review aims to highlight some of the most commonly and recently investigated biomarkers of penile cancer and to summarize the ongoing registered clinical trials for the management of penile cancer patients.

An Analysis of Nectin-4 (PVRL4) in Penile Squamous Cell Carcinoma

Penile squamous cell carcinoma (PSCC) remains a worldwide healthcare concern with poor outcomes and inadequate therapeutic options. Molecular characterization continues to describe the intricacies of PSCC biology, which vary by human papillomavirus (HPV) infection. Despite these advancements in our understanding, utilization of targeted therapies remains limited and underexplored. In this study, we evaluated the transcript and protein expression of Nectin-4 (PVRL4) in PSCC tumors and evaluated whether this is related to tumor features or clinical outcomes. Using two separate PSCC cohorts, we demonstrate that the majority of tumors have active transcription of Nectin-4. We then validated our findings using immunohistochemistry in a tissue microarray representing 57 patients with PSCC. We identified that Nectin-4 was expressed at higher levels in patients with high-risk HPV infection. No significant differences were identified in tumor characteristics or various clinical endpoints when comparing tumors with high and low Nectin-4 expression. This study demonstrates that Nectin-4 is expressed in PSCC and may represent a novel therapeutic target.

Patient summary

In this study, we evaluated the expression of Nectin-4, a cell surface protein, in tumors from patients with nonmetastatic penile squamous cell carcinoma (PSCC). To our knowledge, this is the first study to describe elevated expression of Nectin-4 in PSCC, which may suggest its utility as a therapeutic target.

HPV infection and 5mC/5hmC epigenetic markers in penile squamous cell carcinoma: new insights into prognostics

BACKGROUND

Penile cancer is one of the most aggressive male tumors. Although it is preventable, the main etiologic causes are lifestyle behaviors and viral infection, such as human papillomavirus (HPV). Long-term epigenetic changes due to environmental factors change cell fate and promote carcinogenesis, being an important marker of prognosis. We evaluated epidemiological aspects of penile squamous cell carcinoma (SCC) and the prevalence of HPV infection using high-risk HPV (hrHPV) and p16^INK4A expression of 224 participants. Global DNA methylation was evaluated through 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC).

RESULTS

The incidence of HPV was 53.2% for hrHPV and 22.32% for p16^INK4a. hrHPV was not related to systemic or lymph node metastasis and locoregional recurrence, nor influenced the survival rate. P16^INK4a seems to be a protective factor for death, which does not affect metastasis or tumor recurrence. Lymph node and systemic metastases and locoregional recurrence increase the risk of death. An increased 5mC mark was observed in penile SCC regardless of HPV infection. However, there is a reduction of the 5hmC mark for p16^INK4a + (P = 0.024). Increased 5mC/5hmC ratio (> 1) was observed in 94.2% of penile SCC, irrespective of HPV infection. Despite the increase in 5mC, it seems not to affect the survival rate (HR = 1.06; 95% CI 0.33-3.38).

CONCLUSIONS

P16^INK4a seems to be a good prognosis marker for penile SCC and the increase in 5mC, an epigenetic mark of genomic stability, may support tumor progression leading to poor prognosis.

Genome wide exploration of the methylome in aggressive B-cell lymphoma in Golden Retrievers reveals a conserved hypermethylome

Few recurrent DNA mutations are seen in aggressive canine B cell lymphomas (cBCL), suggesting other frequent drivers. The methylated island recovery assay (MIRA-seq) or methylated CpG-binding domain sequencing (MBD-seq) was used to define the genome-wide methylation profiles in aggressive cBCL in Golden Retrievers to determine if cBCL can be better defined by epigenetic changes than by DNA mutations. DNA hypermethylation patterns were relatively homogenous within cBCL samples in Golden Retrievers, in different breeds and in geographical regions. Aberrant hypermethylation is thus suspected to be a central and early event in cBCL lymphomagenesis. Distinct subgroups within cBCL in Golden Retrievers were not identified with DNA methylation profiles. In comparison, the methylome profile of human DLBCL (hDLBCL) is relatively heterogeneous. Only moderate similarity between hDLBCL and cBCL was seen and cBCL likely cannot be accurately classified into the subtypes seen in hDLBCL. Genes with hypermethylated regions in the promoter-TSS-first exon of cBCL compared to normal B cells often also had additional hyper- and hypomethylated regions distributed throughout the gene suggesting non-randomized repeat targeting of key genes by epigenetic mechanisms. The prevalence of hypermethylation in transcription factor families in aggressive cBCL may represent a fundamental step in lymphomagenesis.

Interplay Between Immune and Cancer-Associated Fibroblasts: A Path to Target Metalloproteinases in Penile Cancer

Extracellular matrix (ECM) remodeling and inflammation have been reported in penile carcinomas (PeCa). However, the cell types and cellular crosstalk involved in PeCa are unexplored. We aimed to characterize the complexity of cells and pathways involved in the tumor microenvironment (TME) in PeCa and propose target molecules associated with the TME. We first investigated the prognostic impact of cell types with a secretory profile to identify drug targets that modulate TME-enriched cells. The secretome analysis using the PeCa transcriptome revealed the enrichment of inflammation and extracellular matrix pathways. Twenty-three secreted factors were upregulated, mainly collagens and matrix metalloproteinases (MMPs). The deregulation of collagens and MMPs was confirmed by Quantitative reverse transcription - polymerase chain reaction (RT-qPCR). Further, the deconvolution method (digital cytometry) of the bulk samples revealed a high proportion of macrophages and dendritic cells (DCs) and B cells. Increased DCs and B cells were associated with better survival. A high proportion of cancer-associated fibroblasts (CAFs) was observed in low-survival patients. Patients with increased CAFs had decreased immune cell proportions. The treatment with the MMP inhibitor GM6001 in CAF cells derived from PeCa resulted in altered cell viability. We reported a crosstalk between immune cells and CAFs, and the proportion of these cell populations was associated with prognosis. We demonstrate that a drug targeting MMPs modulates CAFs, expanding the therapeutic options of PeCa.

Upregulated miRNAs on the TP53 and RB1 Binding Seedless Regions in High-Risk HPV-Associated Penile Cancer

Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1, respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions.

Epigenetic and Transcriptomic Regulation Landscape in HPV+ Cancers: Biological and Clinical Implications

Human Papillomavirus (HPV) is an oncogenic virus that causes the highest number of viral-associated cancer cases and deaths worldwide, with more than 690,000 new cases per year and 342,000 deaths only for cervical cancer (CC). Although the incidence and mortality rates for CC are declining in countries where screening and vaccination programs have been implemented, other types of cancer in which HPV is involved, such as oropharyngeal cancer, are increasing, particularly in men. Mutational and transcriptional profiles of various HPV-associated neoplasms have been described, and accumulated evidence has shown the oncogenic capacity of E6, E7, and E5 genes of high-risk HPV. Interestingly, transcriptomic analysis has revealed that although a vast majority of the human genome is transcribed into RNAs, only 2% of transcripts are translated into proteins. The remaining transcripts lacking protein-coding potential are called non-coding RNAs. In addition to the transfer and ribosomal RNAs, there are regulatory non-coding RNAs classified according to size and structure in long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and small RNAs; such as microRNAs (miRNAs), piwi-associated RNAs (piRNAs), small nucleolar RNAs (snoRNAs) and endogenous short-interfering RNAs. Recent evidence has shown that lncRNAs, miRNAs, and circRNAs are aberrantly expressed under pathological conditions such as cancer. In addition, those transcripts are dysregulated in HPV-related neoplasms, and their expression correlates with tumor progression, metastasis, poor prognosis, and recurrence. Nuclear lncRNAs are epigenetic regulators involved in controlling gene expression at the transcriptional level through chromatin modification and remodeling. Moreover, disruption of the expression profiles of those lncRNAs affects multiple biological processes such as cell proliferation, apoptosis, and migration. This review highlights the epigenetic alterations induced by HPV, from infection to neoplastic transformation. We condense the epigenetic role of non-coding RNA alterations and their potential as biomarkers in transformation’s early stages and clinical applications. We also summarize the molecular mechanisms of action of nuclear lncRNAs to understand better their role in the epigenetic control of gene expression and how they can drive the malignant phenotype of HPV-related neoplasia. Finally, we review several chemical and epigenetic therapy options to prevent and treat HPV-associated neoplasms.

RGS20 Promotes Tumor Progression through Modulating PI3K/AKT Signaling Activation in Penile Cancer

Regulator of G protein signaling 20 (RGS20) plays an important role in regulating neuronal G protein-coupled receptor signaling; however, its expression and oncogenic function in penile cancer (PC) remains unclear. Here, we observed high RGS20 expression in PC tissues compared to normal/adjacent penile tissues, which was closely associated with tumor stage, nodal status, and pelvic metastasis in our PC cohort. The cellular functional analysis of RGS20 revealed that manipulation of the RGS20 expression markedly affected cell viability, BrdU incorporation, soft agar clonogenesis, caspase-3 activity, and cell migration/invasion in PC cell models. Moreover, RGS20 could interact with PI3K p85α subunit and regulate PI3K/AKT signaling activation in PC cell lines. Knockdown of the PI3K p85α or p110α subunit attenuated cell viability, BrdU incorporation, soft agar clonogenesis, and cell migration/invasion in PC cell lines. In contrast, the overexpression of constitutively activated PI3K p110α mutant restored cell proliferation and cell migration/invasion caused by RGS20 depletion in PC cells. Consistent with the in vitro findings, RGS20 depletion attenuated PI3K/AKT signaling activation and suppressed tumor growth in a murine xenograft model. Importantly, the high RGS20 expression was associated with PI3K/AKT signaling activation and unfavorable progression-free/overall survival, highlighting the clinical relevance of RGS20/PI3K/AKT signaling in PC. In conclusion, the aberrant RGS20 expression may serve as a diagnostic and prognostic marker for PC. RGS20 may promote PC progression through modulating PI3K/AKT signaling activation, which may assist with the development of RGS20-targeting therapeutics in the future.

RAB20 Promotes Proliferation via G2/M Phase through the Chk1/cdc25c/cdc2-cyclinB1 Pathway in Penile Squamous Cell Carcinoma

RAB20, a member of the RAS GTPase oncogene family, is overexpressed in several cancers with poor outcomes, promoting tumorigenesis and inducing genomic instability. Here, we performed comprehensive genomic sequencing on eight penile squamous cell carcinoma (PSCC) and normal tissue pairs and found that RAB20 was upregulated in tumors, especially in metastatic lymph nodes. RAB20 overexpression in tumors was further verified by qPCR, Western blotting, and immunohistochemistry of our newly established PSCC cell lines and paired tissues. The clinical significance of RAB20 was validated in 259 PSCC patients, the largest cohort to date, and high RAB20 expression positively correlated with the T, N, M status, extranodal extension, and clinical stage (all p < 0.01). RAB20 was an unfavorable independent prognostic indicator in the survival analysis (p = 0.011, HR = 2.090; 95% Cl: 1.183−4.692), and PSCC patients with high RAB20 expression experienced shorter 5-year cancer-specific survival times (p < 0.001). Furthermore, tumorigenesis assays demonstrated that RAB20 knockdown inhibited cell proliferation, migration, and colony formation in vitro and tumor growth in vivo. RAB20 depletion also induced PSCC cell cycle arrest at G2/M by increasing Chk1 expression and promoting cdc25c phosphorylation to reduce cdc2-cyclinB1 complex formation. Our study revealed an oncogenic role for RAB20 in promoting PSCC cell proliferation at the G2/M phase via the Chk1/cdc25c/cdc2-cyclinB1 pathway. Thus, RAB20 could be a promising prognostic biomarker of advanced PSCC with poor patient survival outcomes and could be a potential therapeutic target.

Systemic treatment of penile squamous cell carcinoma-hurdles and hopes of preclinical models and clinical regimens: a narrative review

Despite contemporary research efforts, the prognosis of penile squamous cell carcinoma (PeSCC) has not significantly improved over the past decade. Despite frequently encountered patient-related delayed medical consultations impairing outcomes, several other aspects contribute to the lack of advancement in the treatment of this condition. One essential reason is that translational research, a prerequisite for the clinically successful disease management, is still at an early stage in PeSCC as compared to many other malignancies. Preclinical experimental models are indispensable for the evaluation of tumor biology and identification of genomic alterations. However, since neither commercial PeSCC cell lines are available nor xenograft models sustainably established, such analyses are challenging in this field of research. In addition, systemic therapies are less effective and toxic without decisive breakthroughs over recent years. Current systemic management of PeSCC is based on protocols that have been investigated in small series of only up to 30 patients. Thus, there is an unmet medical need for new approaches necessitating research efforts to develop more efficacious systemic strategies. This review aims to highlight the current state of knowledge in the molecular alterations involved in the etiology and ensuing steps for cancer progression, existing preclinical models of translational research, clinically relevant systemic protocols, and ongoing clinical trials.

DKK1 inhibits canonical Wnt signaling in human papillomavirus-positive penile cancer cells

•

Elevated expression of Wnt pathway associated factors in HPV-positive penile cancer cells.

•

lacking nuclear beta-catenin translocation indicated an actively abrogated Wnt signaling.

•

elevated expression of the Wnt antagonist DKK1 in HPV-positive penile cancer cells.

•

DKK1-driven autocrine Wnt pathway inhibition in penile cancer cells.

•

DKK1⁺ penile cancers are with a higher frequency HPV⁺, less differentiated and grow more aggressively.

Penile squamous cell cancer (PSCC) is the most frequent penile malignant disease. Infections with human papillomaviruses (HPV) are a major etiologic driver of PSCC. However, the molecular details of the underlying carcinogenesis are understudied because of rare clinical specimens and missing cell lines. Here, we investigated if the expression of high-risk HPV16 oncogenes causes an augmentation of the Wnt pathway using unique HPV-positive penile cancer (PeCa) cell lines in monolayer and organotypic 3D raft cultures as well as tissue micro arrays containing clinical tissue specimens. The HPV oncoproteins enhanced the expression of Leucine-rich repeat-containing G-protein coupled receptor 6 (LGR6) and the HPV-positive PeCa cells expressed a signature of Wnt target and stemness-associated genes. However, the notable lack of nuclear β-catenin in vitro and in situ raised the question if the enhanced expression of Wnt pathway factors is tantamount to an active Wnt signaling. Subsequent TOP-flash reporter assays revealed Wnt signaling as absent and not inducible by respective Wnt ligands in PeCa cell lines. The HPV-positive PeCa cells and especially HPV-positive PeCa specimens of the tumor core expressed the Wnt antagonist and negative feedback-regulator Dickkopf1 (DKK1). Subsequent neutralization experiments using PeCa cell line-conditioned media demonstrated that DKK1 is capable to impair ligand-induced Wnt signaling. While gene expression analyses suggested an augmented and active canonical Wnt pathway, the respective signaling was inhibited due to the endogenous expression of the antagonist DKK1. Subsequent TMA stainings indicated Dkk1 as linked with HPV-positivity and metastatic disease progression in PeCa suggesting potential as a prognostic marker.

Disruption of miRNA-mRNA Networks Defines Novel Molecular Signatures for Penile Carcinogenesis

Penile cancer (PeC) carcinogenesis is not fully understood, and no biomarkers are reported in clinical practice. We aimed to investigate molecular signatures based on miRNA and mRNA and perform an integrative analysis to identify molecular drivers and pathways for PeC development. Affymetrix miRNA microarray was used to identify differentially expressed miRNAs (DEmiRs) comparing 11 tumoral tissues (TT) paired with non-neoplastic tissues (NNT) with further validation in an independent cohort (n = 13). We also investigated the mRNA expression of 83 genes in the total sample. Experimentally validated targets of DEmiRs, miRNA-mRNA networks, and enriched pathways were evaluated in silico. Eight out of 69 DEmiRs identified by microarray analysis were validated by qRT-PCR (miR-145-5p, miR-432-5p, miR-487b-3p, miR-30a-5p, miR-200a-5p, miR-224-5p, miR-31-3p and miR-31-5p). Furthermore, 37 differentially expressed genes (DEGs) were identified when comparing TT and NNT. We identified four downregulated DEmiRs (miR-30a-5p, miR-432-5p, miR-487b-3p, and miR-145-5p) and six upregulated DEGs (IL1A, MCM2, MMP1, MMP12, SFN and VEGFA) as potential biomarkers in PeC by their capacity of discriminating TT and NNT with accuracy. The integration analysis showed eight dysregulated miRNA-mRNA pairs in penile carcinogenesis. Taken together, our findings contribute to a better understanding of the regulatory roles of miRNAs and altered transcripts levels in penile carcinogenesis.

Penile Cancer-Derived Cells Molecularly Characterized as Models to Guide Targeted Therapies

Penile cancer (PeCa) is a common disease in poor and developing countries, showing high morbidity rates. Despite the recent progress in understanding the molecular events involved in PeCa, the lack of well-characterized in vitro models precludes new advances in anticancer drug development. Here we describe the establishment of five human primary penile cancer-derived cell cultures, including two epithelial and three cancer-associated fibroblast (CAF) cells. Using high-throughput genomic approaches, we found that the epithelial PeCa derived- cells recapitulate the molecular alterations of their primary tumors and present the same deregulated signaling pathways. The differentially expressed genes and proteins identified are components of key oncogenic pathways, including EGFR and PI3K/AKT/mTOR. We showed that epithelial PeCa derived cells presented a good response to cisplatin, a common therapeutic approach used in PeCa patients. The growth of a PeCa-derived cell overexpressing EGFR was inhibited by EGFR inhibitors (cetuximab, gefitinib, and erlotinib). We also identified CAF signature markers in three PeCa-derived cells with fibroblast-like morphology, indicating that those cells are suitable models for PeCa microenvironment studies. We thus demonstrate the utility of PeCa cell models to dissect mechanisms that promote penile carcinogenesis, which are useful models to evaluate therapeutic approaches for the disease.

Experimental Models for Studying HPV-Positive and HPV-Negative Penile Cancer: New Tools for An Old Disease

Simple Summary

Penile cancer is an uncommon and understudied malignancy that is most commonly diagnosed in developing countries. Therapeutic advances have been slow, in part due to the lack of in vitro and in vivo models for testing new drugs before performing clinical trials. Recently, this difficulty has been partly overcome and multiple new pre-clinical models were reported. These important developments will help develop new therapies for penile cancer patients. The present review summarizes and discusses the available data concerning the pre-clinical models of penile cancer and their uses. Comparisons are drawn between different models, allowing researchers to choose the most adequate setting for their experiments. The remaining gaps in this array of penile cancer models are also discussed, in particular the lack of models for studying metastatic disease and cell lines representing tumors associated with human papillomavirus.

Abstract

Penile cancer is an uncommon malignancy that occurs most frequently in developing countries. Two pathways for penile carcinogenesis are currently recognized: one driven by human papillomavirus (HPV) infection and another HPV-independent route, associated with chronic inflammation. Progress on the clinical management of this disease has been slow, partly due to the lack of preclinical models for translational research. However, exciting recent developments are changing this landscape, with new in vitro and in vivo models becoming available. These include mouse models for HPV⁺ and HPV⁻ penile cancer and multiple cell lines representing HPV⁻ lesions. The present review addresses these new advances, summarizing available models, comparing their characteristics and potential uses and discussing areas that require further improvement. Recent breakthroughs achieved using these models are also discussed, particularly those developments pertaining to HPV-driven cancer. Two key aspects that still require improvement are the establishment of cell lines that can represent HPV⁺ penile carcinomas and the development of mouse models to study metastatic disease. Overall, the growing array of in vitro and in vivo models for penile cancer provides new and useful tools for researchers in the field and is expected to accelerate pre-clinical research on this disease.

Identification of a methylation panel aid in risk stratification in node-positive penile squamous cell carcinoma

Molecular prognostic factors for individualized treatment of squamous cell carcinoma (SCC) are poorly defined. Our study developed and validated a novel molecular tools aid in preinguinal and postinguinal lymphadenectomy risk stratification in node-positive penile SCC. Patients with node-positive penile SCC who underwent inguinal or ilioinguinal lymphadenectomy were divided into three cohorts: a discovery set, a development set and a validation set. The local ethics committee approved the study. The primary endpoint was cancer-specific survival (CSS). At the discovery stage, 17 CpG sites were significantly associated with CSS. In the development set, we constructed a 3-CpG-based prognostic score for survival prediction. The hazard ratio (HR) of the panel (dichotomized using the optimal cutoff) was 5.8 in the multivariate analyses (P < .001). The addition of the methylation score significantly improved the pN-stage C-index from 0.70 to 0.79 (incremental C = 0.09, P < .001). In the validation set, the methylation panel showed a HR of 9.9 in the multivariate analyses. The addition of the molecular marker improved the pN-stage C-index from 0.69 to 0.78 (incremental C = 0.09, P < .001). The methylation score remarkably separated survival curves in different pN stages, which indicate that the tool can be applied to tailor the treatment in both preinguinal and postinguinal lymphadenectomy settings. We developed and validated a prognostic methylation panel for node-positive penile SCC. The tool may aid in the risk stratification of the population with heterogeneous outcomes and needs prospective validation. Patients in high-risk group may benefit from more aggressive therapy or clinical trials.

High serum CCL20 is associated with tumor progression in penile cancer

Serum cancer biomarker has been proven to be very valuable in cancer diagnosis, disease monitoring and prognosis assessment, despite there is still a lack of serum biomarker for penile cancer (PC). Our initial analysis on public GEO dataset identified CCL20 as a top C-C motif ligand (CCL) gene enriched in PC. The patients with PC exhibited markedly higher preoperative serum CCL20 level than healthy control. The area under the curve (AUC) was 0.855 with the sensitivity of 72.4%, and specificity of 93.5% to distinguish PC. Preoperative serum CCL20 level was significantly associated with clinicopathological characteristics including T stage (P=0.005), nodal status (P=0.008), and pelvic lymph node metastasis (P=0.007). PC Patients with high serum CCL20 level had shorter disease-free survival compared to those with low level (P<0.001). Cox regression analysis showed that serum CCL20 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.980 (95% CI: 1.209-13.098, P=0.023). Furthermore, CCL20 expression was observed in PC tissues and cell lines. Knockdown of CCL20 expression markedly suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and AKT signaling and reduced MMP2/9 secretion in PC cell lines. Consistently, CCL20 and its receptor CCR6 exhibited correlated expression pattern in PC tissues. In conclusion, serum CCL20 level might serve as a potential diagnostic and prognostic cancer biomarker for PC. CCL20 might activate multiple downstream oncogenic signaling pathways (STAT3, AKT, MMP2/9) to promote malignant progression of PC, which may warrant further investigation in the future.

SHCBP1 regulates STAT3/c-Myc signaling activation to promote tumor progression in penile cancer

A challenge in developing novel strategies for penile cancer (PC) is the limited understanding of the regulatory mechanisms involved in PC development. This study aims to examine the expression of SHC SH2 Domain-Binding Protein 1 (SHCBP1) in PC and to explore its oncogenic function. Aberrant SHCBP1 expression was observed in PC tissues compared with normal penile tissues. SHCBP1 expression was significantly associated with the pathological grade, T stage, nodal status, and pelvic lymph node metastasis, and could serve as an independent factor for unfavorable overall survival in PC. Manipulation of SHCBP1 expression affected cell proliferation, soft agar clonogenesis, and cell migration and invasion in PC cell lines. Moreover, we identified STAT3/c-Myc signaling as a potential downstream target of SHCBP1. SHCBP1 interacted with JAK2 and STAT3 upon EGF stimulation, which might regulate STAT3/c-Myc signaling activation in PC cells. Disruption of STAT3/c-Myc signaling attenuated cell proliferation and cell migration/invasion in PC cell lines. Nevertheless, overexpression of constitutively activated STAT3 or c-Myc rescued cell proliferation and cell migration/invasion caused by SHCBP1 depletion in PC cell lines. Consistently, SHCBP1 depletion attenuated STAT3/c-Myc signaling and suppressed tumor growth in a murine xenograft model. Importantly, correlated expression of SHCBP1, p-STAT3, and c-Myc was observed in PC tissues, confirming the clinical relevance of SHCBP1/STAT3/c-Myc signaling in PC. In conclusion, aberrant SHCBP1 expression could serve as a potential prognostic biomarker for PC. SHCBP1 might activate the STAT3/c-Myc signaling pathway to promote tumor progression in PC, which may serve as a potential target for PC treatment.

Serum CXCL13 Level is Associated with Tumor Progression and Unfavorable Prognosis in Penile Cancer

Background

Chemokine (C-X-C motif) ligands (CXCLs) are important regulators of tumor progression in many cancers and could serve as potential cancer biomarkers. However, the expression patterns as well as functions of CXCLs remain unclear in penile cancer (PC). The aim of this study was to evaluate the usefulness of serum CXCL13 as a potential cancer biomarker for PC.

Patients and Methods

This retrospective study enrolled 76 patients diagnosed with PC between 2016 and 2018. Serum CXCL13 level was detected by enzyme-linked immunosorbent assay. Univariable and multivariable Cox regression analyses were conducted to identify the prognostic factors that influence disease-free survival. Human penile cancer cell lines Penl1, Penl2, 149RCa and LM156 were used as in vitro models. The expression of CXCL13 protein in PC cell lines was analyzed by Western blotting.

Results

Our initial analysis on GSE57955 dataset identified CXCL13 as a top CXCL gene enriched in PC. Higher preoperative serum CXCL13 level was detected in PC cohorts than in healthy male controls (P<0.001). The area under the curve was 0.911 with the sensitivity of 84.2% and specificity of 87.0% to distinguish PC. Preoperative serum CXCL13 level was associated with pathological grade (P=0.048), T stage (P=0.009), nodal status (P<0.001) and pelvic lymph node metastasis (P=0.005) in PC. Serum CXCL13 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.818 (95%CI: 1.126–12.946). Furthermore, autocrine expression of CXCL13 was detected in PC tissues and cell lines. Knockdown of CXCL13 expression suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and ERK1/2 signaling and reduced MMP2/9 secretion in PC cell lines.

Conclusion

Serum CXCL13 could serve as a novel diagnostic and prognostic biomarker for PC. CXCL13 signaling might activate oncogenic signaling pathways to promote malignant progression of PC.

Methylation in HOX Clusters and Its Applications in Cancer Therapy

HOX genes are commonly known for their role in embryonic development, defining the positional identity of most structures along the anterior–posterior axis. In postembryonic life, HOX gene aberrant expression can affect several processes involved in tumorigenesis such as proliferation, apoptosis, migration and invasion. Epigenetic modifications are implicated in gene expression deregulation, and it is accepted that methylation events affecting HOX gene expression play crucial roles in tumorigenesis. In fact, specific methylation profiles in the HOX gene sequence or in HOX-associated histones are recognized as potential biomarkers in several cancers, helping in the prediction of disease outcomes and adding information for decisions regarding the patient’s treatment. The methylation of some HOX genes can be associated with chemotherapy resistance, and its identification may suggest the use of other treatment options. The use of epigenetic drugs affecting generalized or specific DNA methylation profiles, an approach that now deserves much attention, seems likely to be a promising weapon in cancer therapy in the near future. In this review, we summarize these topics, focusing particularly on how the regulation of epigenetic processes may be used in cancer therapy.

Effective combinatorial immunotherapy for penile squamous cell carcinoma

Penile squamous cell carcinoma (PSCC) accounts for over 95% of penile malignancies and causes significant mortality and morbidity in developing countries. Molecular mechanisms and therapies of PSCC are understudied, owing to scarcity of laboratory models. Herein, we describe a genetically engineered mouse model of PSCC, by co-deletion of Smad4 and Apc in the androgen-responsive epithelium of the penis. Mouse PSCC fosters an immunosuppressive microenvironment with myeloid-derived suppressor cells (MDSCs) as a dominant population. Preclinical trials in the model demonstrate synergistic efficacy of immune checkpoint blockade with the MDSC-diminishing drugs cabozantinib or celecoxib. A critical clinical problem of PSCC is chemoresistance to cisplatin, which is induced by Pten deficiency on the backdrop of Smad4/Apc co-deletion. Drug screen studies informed by targeted proteomics identify a few potential therapeutic strategies for PSCC. Our studies have established what we believe to be essential resources for studying PSCC biology and developing therapeutic strategies.

Genomic profiling reveals the pivotal role of hrHPV driving copy number and gene expression alterations, including mRNA downregulation of TP53 and RB1 in penile cancer

The incidence of penile cancer (PeCa) is increasing worldwide, however, the highest rates are reported in underdeveloped countries. The molecular mechanisms that underly the onset and progression of these tumors are still unclear. Therefore, our goal was to determine the genome-wide copy number alterations and the involvement of human papiloma virus (HPV) (TP53 and RB1), inflammatory (COX2 and EGFR), and PI3K/AKT pathway (AKT1, AKT2, EGFR, ERBB3, ERBB4, PIK3CA, and PTEN) associated genes in patients with PeCa from a high incidence region in Brazil (Maranhão). HPV genotyping was performed by nest-PCR and genome sequencing, copy number alterations (CNAs) by array comparative genomic hybridization and gene copy number status, gene, and protein expression by quantitative polymerase chain reaction, reverse transcriptase-quantitative polymerase chain reaction, and immunohistochemistry, respectively. HPV genotyping revealed one of the highest frequencies of HPV reported in PeCa, affecting 96.4% of the cases. The most common CNAs observed were located at the HPV integration sites, such as 2p12-p11.2 and 14q32.33, where ADAM 6, KIAA0125, LINC00226, LINC00221, and miR7641-2, are mapped. Increased copy number of ERBB3 and EGFR genes were observed in association with COX2 and EGFR overexpression, reinforcing the role of the inflammatory pathway in PeCa, and suggesting anti-EGFR and anti-COX2 inhibitors as promising therapies for PeCa. Additionally, TP53 and RB1 messenger RNA downregulation was observed, suggesting the occurrence of other mechanisms for repression of these oncoproteins, in addition to the canonical HPV/TP53/RB1 signaling pathway. Our data reinforce the role of epigenetic events in abnormal gene expression in HPV-associated carcinomas and suggest the pivotal role of HPV driving CNAs and controlling gene expression in PeCa.

Genetics and penile cancer: recent developments and implications

PURPOSE OF REVIEW

We summarize the recent developments in the molecular landscape of penile squamous cell carcinoma (PSCC).

RECENT FINDINGS

Recent genomic studies have demonstrated a molecular convergence of PSCC with other squamous cell carcinomas (SCCs) from different organ sites. Similarly, human papillomavirus (HPV)-related PSCCs appear to have epigenetic and genomic similarities with other HPV-related cancers. This could have implications on future HPV-related cancer trial design. Growing efforts to characterize recurrent gene alterations in PSCC have expanded our understanding over the past years, showing a predominance of tumor suppressor gene alterations such as TP53 and NOTCH1. In addition, these studies have demonstrated that at least 30% of PSCC cases have targetable gene alterations. Further, the similar tumor mutational burden with other SCCs and the relatively high rates of programmed death-1 (PD-1) positive expression in PSCC constitute the rationale for investigation of PD-1 inhibition in ongoing clinical trials. Multiple studies have identified potential epigenetic and RNA signatures predictive of metastasis or survival, but these still require validation in larger cohorts.

SUMMARY

PSCC appears to be genomicaly similar to other SCCs and HPV-related cancers. This provides the rationale and opportunity to include a rare tumor like PSCC in future 'basket type' trials using novel agents targeting multiple SCCs that may exhibit similar biology.

Incorporating DNA Methyltransferase Inhibitors (DNMTis) in the Treatment of Genitourinary Malignancies: A Systematic Review

Inhibition of DNA methyltransferases (DNMTs) has emerged as a novel treatment strategy in solid tumors. Aberrant hypermethylation in promoters of critical tumor suppressor genes is the basis for the idea that treatment with hypomethylating agents may lead to the restoration of a "normal" epigenome and produce clinically meaningful therapeutic outcomes. The aim of this review article is to summarize the current state of knowledge of DNMT inhibitors in the treatment of genitourinary malignancies. The efficacy of these agents in genitourinary malignancies was reported in a number of studies and suggests a role of induced DNA hypomethylation in overcoming resistance to conventional cytotoxic treatments. The clinical significance of these findings should be further investigated.

MEIS transcription factors in development and disease

MEIS transcription factors are key regulators of embryonic development and cancer. Research on MEIS genes in the embryo and in stem cell systems has revealed novel and surprising mechanisms by which these proteins control gene expression. This Primer summarizes recent findings about MEIS protein activity and regulation in development, and discusses new insights into the role of MEIS genes in disease, focusing on the pathogenesis of solid cancers.

High TRIAP1 expression in penile carcinoma is associated with high risk of recurrence and poor survival

Background

TP53-regulated inhibitor of apoptosis 1 (TRIAP1), also known as p53 cell survival factor or p53CSV, is reported to be associated with resistance of apoptosis in different human malignancies, but the potential role of TRIAP1 in penile carcinoma (PeCa) has not been well studied. This study aimed to analyze the association between TRIAP1 expression and clinical outcome in PeCa patients.

Methods

Bioinformatics was used to analyze the differential TRIAP1 expression in PeCa compared with normal tissues in Gene Expression Omnibus (GEO) Dataset (GSE57955). The expression of TRIAP1 in tumor specimens from 57 patients undergoing radical penile surgery was detected by immunohistochemistry (IHC). Differential TRIAP1 expression in various human malignancies was also assessed by GEPIA web-tool based on The Cancer Genome Atlas (TCGA) Datasets. Subsequently, the relationship between TRIAP1 expression and clinical prognosis of PeCa patients was analyzed.

Results

Both IHC and GEO Dataset (GSE57955) showed that TRIAP1 was significantly overexpressed in PeCa tissues when compared with normal tissues. Based on patient data and IHC on clinical specimens, we found that strong intensity of TRIAP1 expression was significantly related with higher histological grade (P=0.049) and elevated local recurrence rate (P=0.023), suggesting TRIAP1 as a potential predictor in recurrence. Further, high TRIAP1 expression was identified to be a hazardous prognostic factor for local recurrence-free survival (RFS).

Conclusions

High TRIAP1 expression in PeCa is associated with high risk of recurrence and poor survival, suggesting TRIAP1 may become a potential prognostic factor for PeCa.

Statistical methods for classification of 5hmC levels based on the Illumina Inifinium HumanMethylation450 (450k) array data, under the paired bisulfite (BS) and oxidative bisulfite (oxBS) treatment

Hydroxymethylcytosine (5hmC) methylation is a well-known epigenetic mark that is involved in gene regulation and may impact genome stability. To investigate a possible role of 5hmC in cancer development and progression, one must be able to detect and quantify its level first. In this paper, we address the issue of 5hmC detection at a single base resolution, starting with consideration of the well-established 5hmC measure Δβ and, in particular, with an analysis of its properties, both analytically and empirically. Then we propose several alternative hydroxymethylation measures and compare their properties with those of Δβ. In the absence of a gold standard, the (pairwise) resemblance of those 5hmC measures to Δβ is characterized by means of a similarity analysis and relative accuracy analysis. All results are illustrated on matched healthy and cancer tissue data sets as derived by means of bisulfite (BS) and oxidative bisulfite converting (oxBS) procedures.

Integrated miRNA and mRNA expression analysis uncovers drug targets in laryngeal squamous cell carcinoma patients

OBJECTIVES

The current treatment of laryngeal squamous cell carcinoma (LSCC) is based on radical surgery and radiotherapy resulting in high morbidity. Chemoradiotherapy has been used as alternative to organ sparing; however, several advanced cases presented resistance to treatment, which contributes to a high risk of recurrence and mortality. Coding RNAs and miRNAs have potential to be used as biomarkers or targets for cancer therapy.

MATERIALS AND METHODS

In this study, 36 LSCC and 5 non-neoplastic control samples were investigated using miRNA and mRNA large-scale expression analysis and a cross-validation was performed using the TCGA database (116 LSCC and 12 surrounding normal tissues).

RESULTS

The large-scale profiling revealed the involvement of 28 miRNAs and 817 genes differentially expressed in LSCC. An integrative analysis comprising predicted and experimentally validated miRNA/mRNA interactions (negatively correlated), resulted in 28 miRNAs and 543 mRNAs. Decreased expression of miR-199b was significantly associated with shorter disease-free survival in LSCC (internal and TCGA datasets). The expression levels of selected miRNAs (miR-199b-5p, miR-29c-3p, miR-204-5p, miR-125b-5p and miR-92a-3p) and genes (COL3A1, COL10A1, ERBB4, HMGA2, HLF, TOP2A, MMP3, MMP13, MMP10 and PPP1R3) were confirmed as altered in LSCC by RT-qPCR. Additionally, a drug target prediction analysis revealed drug combinations based on miRNA and mRNA expression, pointing out novel alternatives to optimize the LSCC treatment.

CONCLUSION

Collectively, these findings provide new insights in the LSCC transcriptional deregulation and potential drug targets.

Association between Human Papillomavirus and Non-cervical Genital Cancers in Brazil: A Systematic Review and Meta-Analysis

Background: Human papillomavirus (HPV) infection is associated with cervical cancer; however, it is controversial whether it is involved in non-cervical genital cancers. Objective: This study aimed to evaluate articles on the prevalence of HPV in penile cancer, vulvar cancer, colorectal cancer, prostate cancer and anal canal cancer in studies conducted in Brazil. Methods: The study was conducted in accordance with the Preferred Reporting of Systematic Reviews and Meta-Analysis Statement. Comprehensive searches for HPV and cancer for the years 2006 to 2016 were conducted in two databases (PubMed and Web of Knowledge) and Google Scholar system. We also tracked the references of all eligible articles to identify additional non-captured publications through online surveys. Results: Eighteen studies, with a combined sample size of 1,552 patients were analyzed. The overall prevalence of HPV was 43% (95% CI: 36–51%; p < 0.001). The pooled prevalence of HPV in penile cancer was 42% (95% CI: 32–55%; p < 0.001), in colorectal cancer it was 67% (95% CI: 64–70%; p < 0.001) and in vulvar cancer 43% (95% CI: 34–55%; p < 0.001). HPV 16 was the most prevalent in all sites evaluated, with prevalence estimated at 54% (95% CI: 44–66%; p < 0.001), followed by genotypes 33 (21%; 95% CI: 17–28; p < 0.001), 6 (15%; 95% CI: 8–26%; p < 0.001), 11 (13%; 95% CI: 5–32%; p < 0.001) and 18 (12%; 95% CI: 7–22%; p < 0.001), respectively. The pooled prevalence of single infection was 82% and infection by multiple genotypes of HPV was 22%. Conclusion: Our study demonstrated a high prevalence of HPV in non-cervical genital cancers in Brazil, with predominance of genotype 16, providing evidence for the need for preventive and control measures to avoid future harm to the population.

Nuclear loss and cytoplasmic expression of androgen receptor in penile carcinomas: role as a driver event and as a prognosis factor

Androgen receptor (AR) is a member of the steroid and nuclear family receptor that acts as transcription factor. AR signaling plays pivotal role in the development and progression of prostate cancer. However, the role of AR in penile cancer (PeCa) is poorly explored. Our previous molecular studies unveiled frequent AR mRNA loss in PeCa, which was further predicted as a major driver alteration in this neoplasm. Herein, we assessed the AR protein expression in 59 usual PeCa tissues and 42 surrounding normal tissues (SNT) by immunohistochemistry using a tissue microarray. In a paired analysis, we found a total absence of nuclear AR expression in PeCa while 95.2% of SNT samples presented strong nuclear AR expression (P < 0.001). Interestingly, 17 of 42 PeCa presented weak or moderate cytoplasmic AR staining, contrasting with 5 of 42 SNT (P = 0.008). Increased levels of AR cytoplasmic expression were related with poor prognosis features including advanced clinical staging (P = 0.044), compromised surgical margins (P = 0.005), and pathological inguinal node status (P = 0.047). Furthermore, AR cytoplasmic expression was also related with shorter overall survival (P = 0.032). In conclusion, the frequent loss of nuclear AR protein levels suggests a potential function in PeCa development. Based on this result, the androgen deprivation therapy is not indicated for PeCa patients. In addition, the AR cytoplasmic expression found in a significant number of cases (40.5%) showed prognostic value and pathways activated by the non-genomic AR signaling may represent a promising therapeutic strategy.

Downregulation of HOXA3 in lung adenocarcinoma and its relevant molecular mechanism analysed by RT-qPCR, TCGA and in silico analysis

Recent studies have indicated that homeobox A3 (HOXA3) functions as a carcinogen in colon cancer and the methylation level of HOXA3 is significantly increased in lung adenocarcinoma (LUAD) tissues. However, at least to the best of our knowledge, few studies to date have been performed on HOXA3 in non-small cell lung cancer (NSCLC). Therefore, further studies on HOXA3 expression in NSCLC and the potential regulatory mechanisms are urgently required. In this study, HOXA3 expression in 55 tissues of cases of NSCLC and corresponding non-lung cancer tissues was detected by reverse transcription-quantitative PCR (RT-qPCR). In addition, the clinical significance of HOXA3 expression in NSCLC was evaluated using the Cancer Genome Atlas (TCGA) database. Bioinformatics analysis was then performed to elucidate the potential molecular mechanisms of action of HOXA3. Furthermore, the potential target microRNAs (miRNAs or miRs) of HOXA3 were predicted using miRWalk2.0. Based on Gene Expression Omnibus (GEO) and TGCA databases, standardized mean difference (SMD) and sROC methods were used for meta-analyses of the expression of potential target miRNAs of HOXA3 in NSCLC to evaluate their association with HOXA3. The results revealed that the HOXA3 expression levels in NSCLC, LUAD and lung squamous cell carcinoma (LUSC) were 0.1130±0.1398, 0.1295±0.16890 and 0.0906±0.0846, respectively. These values were all decreased compared with the normal tissues (0.1877±0.1975, 0.2337±0.2405 and 0.1249±0.0873, respectively, P<0.05). The TCGA database also revealed the low expression trend of HOXA3. The downregulation of HOXA3 may play an important role in the progression and the poor prognosis of LUAD. The TCGA database also suggested that HOXA3 in LUAD and LUSC tissues exhibited certain mutational levels. In addition, the methylation levels in the NSCLC, LUAD and LUSC tissues significantly increased [NSCLC: fold change (FC), 1.3226; P<0.001; LUAD: FC, 1.2712; P<0.001; and LUSC: FC, 1.3786; P<0.001]. According to the analyses using the Kyoto Encyclopedia of Genes and Genomes (KEGG), we found that the co-expression HOXA3 genes were mainly associated with the focal adhesion signalling pathway and the ECM-receptor interaction signalling pathway. Furthermore, the predicted miRNA, miR-372-3p, exhibited a high expression in both the NSCLC and LUAD tissues (P<0.05). On the whole, the findings of this study indicate that low HOXA3 expression may play a certain role in LUAD; however, its association with LUSC still requires further investigation. HOXA3 function may be achieved through different pathways or target miRNAs. However, the specific underlying mechanisms need to be confirmed through various functional studies.

Relationship between human papillomavirus and penile cancer-implications for prevention and treatment

Penile cancer is a rare disease in the United States, but rates are increasing, causing concern. Several risk factors have been associated with the disease, including human papillomavirus (HPV) infection. Knowledge of HPV pathogenesis has led to the development of a vaccine, which has proven instrumental in reducing the incidence of female HPV-related cancers, but results in men have yet to be elucidated. Fortunately, rates of vaccination are up-trending in both males and females in the past several years. In addition, targeted therapies are the focus of several ongoing research efforts. Some of these therapeutics are currently in use, while several are in trials. With continued patient education and research, both treatment and prevention of HPV-related pre-malignant lesions and penile cancer will likely diminish.

Integrative miRNA and mRNA analysis in penile carcinomas reveals markers and pathways with potential clinical impact

Penile carcinoma (PeCa) is an important public health issue in poor and developing countries, and has only recently been explored in terms of genetic and epigenetic studies. Integrative data analysis is a powerful method for the identification of molecular drivers involved in cancer development and progression. miRNA and mRNA expression profiles followed by integrative analysis were investigated in 23 PeCa and 12 non-neoplastic penile tissues (NPT). Expression levels of eight miRNAs and 10 mRNAs were evaluated in the same set of samples used for microarray and in a validation set of cases (PeCa = 36; NPT = 27). Eighty-one miRNAs and 2,697 mRNAs were identified as differentially expressed in PeCa. Integrative data analysis revealed 255 mRNAs potentially regulated by 68 miRNAs. Using RT-qPCR, eight miRNAs and nine transcripts were confirmed as altered in PeCa. We identified that MMP1, MMP12 and PPARG and hsa-miR-31-5p, hsa-miR-224-5p, and hsa-miR-223-3p were able to distinguish tumors from NPT with high sensitivity and specificity. Higher MMP1 expression was detected as a better predictor of lymph node metastasis than the clinical-pathological data. In addition, PPARG and EGFR were highlighted as potential pathways for targeted therapy in PeCa. The analysis based on HPV positivity (7 of 23 cases) revealed five miRNA and 13 mRNA differentially expressed. Although in a limited number of cases, HPV positive PeCa presented less aggressive phenotype in comparison with negative cases. Overall, an integrative analysis using mRNA and miRNA profiles revealed markers related with tumor development and progression. Furthermore, MMP1 expression level was a predictive marker for lymph node metastasis in patients with PeCa.

Multidimensional integrative analysis uncovers driver candidates and biomarkers in penile carcinoma

Molecular data generation and their combination in penile carcinomas (PeCa), a significant public health problem in poor and underdeveloped countries, remain virtually unexplored. An integrativemethodology combin ing genome-wide copy number alteration, DNA methylation, miRNA and mRNA expression analysis was performed in a set of 20 usual PeCa. The well-ranked 16 driver candidates harboring genomic alterations and regulated by a set of miRNAs, including hsa-miR-31, hsa-miR-34a and hsa-miR-130b, were significantly associated with over-represented pathways in cancer, such as immune-inflammatory system, apoptosis and cell cycle. Modules of co-expressed genes generated from expression matrix were associated with driver candidates and classified according to the over-representation of passengers, thus suggesting an alteration of the pathway dynamics during the carcinogenesis. This association resulted in 10 top driver candidates (AR, BIRC5, DNMT3B, ERBB4, FGFR1, PML, PPARG, RB1, TNFSF10 and STAT1) selected and confirmed as altered in an independent set of 33 PeCa samples. In addition to the potential driver genes herein described, shorter overall survival was associated with BIRC5 and DNMT3B overexpression (log-rank test, P = 0.026 and P = 0.002, respectively) highlighting its potential as novel prognostic marker for penile cancer.

The Emerging Role and Promise of Biomarkers in Penile Cancer

Penile cancer is a rare malignancy, which can be a source of devastating psychosexual distress because of its implication on sexual function and self-image. Current penile staging relies on invasive techniques and is often inaccurate. The authors review the promising biomarkers currently under investigation and their application to the staging and prognosis of penile cancer. Further development of such biomarkers provides the potential of improved clinical management of this disease.

A comprehensive characterization of cell cultures and xenografts derived from a human verrucous penile carcinoma

This study aimed to establish and characterize primary cell cultures and xenografts derived from penile carcinoma (PeCa) in order to provide experimental models for cellular processes and efficacy of new treatments. A verrucous squamous cell carcinoma (VSCC) was macrodissected, dissociated, and cultivated in KSFM/DF12 medium. Cell cultures were evaluated at passage 5 (P5) using migration and invasion assays and were serially propagated, in vivo, in BALB/c nude mice until passage 3 (X1-X3). Immunophenotypic characterization of cultures and xenografts was performed. Genomic (CytoScan HD, Affymetrix) and transcriptomic profiles (HTA 2.0 platform, Affymetrix) for VSCC, cell cultures, and xenografts were assessed. P5 cells were able to migrate, invade the Matrigel, and produce tumors in immunodeficient mice, demonstrating their malignant potential. The xenografts unexpectedly presented a sarcomatoid-like carcinoma phenotype. Genomic analysis revealed a high similarity between the VSCC and tumor-derived xenograft, confirming its xenograft origin. Interestingly, a subpopulation of P5 cells presented stem cell-related markers (CD44(+)CD24(-) and ALDH1(high)) and sphere-forming capacity, suggesting their potential xenograft origin. Cell cultures and xenografts retained the genomic alterations present in the parental tumor. Compared to VSCC, differentially expressed transcripts detected in all experimental conditions were associated with cellular morphology, movement, and metabolism and organization pathways. Malignant cell cultures and xenografts derived from a verrucous penile carcinoma were established and fully characterized. Nevertheless, xenograft PeCa models must be used with caution, taking into consideration the selection of specific cell populations and anatomical sites for cell/tumor implantation.

Integrated Loss of miR-1/miR-101/miR-204 Discriminates Metastatic from Nonmetastatic Penile Carcinomas and Can Predict Patient Outcome

PURPOSE

Penile squamous cell carcinoma is a rare but aggressive cancer. Little is known about pivotal events in tumor pathogenesis and metastasis. Lymph node metastasis is the prevailing prognostic factor while clinical detection in patients remains difficult. Our aim was to identify distinct miRNAs that are differentially expressed in metastatic vs nonmetastatic penile carcinoma, which may serve as diagnostic biomarkers for disease progression.

MATERIALS AND METHODS

TaqMan® arrays and quantitative polymerase chain reaction were applied to analyze miRNA profiles in penile squamous cell carcinoma specimens and glans tissue from 24 patients. The prognostic value of deregulated miRNAs was analyzed using the Kaplan-Meier method. The Spearman test was applied to determine a potential linkage between distinctive miRNAs in individual patients.

RESULTS

Loss of miR-1 (p = 0.0048), miR-101 (p = 0.0001) and miR-204 (p = 0.0004) in metastasizing tumors and associated metastases (p = 0.0151, 0.0019 and 0.0003, respectively) distinguished patients with metastatic and nonmetastatic penile squamous cell carcinoma. These 3 miRNAs showed a coherent expression pattern. Consistently, patients with low levels of all 3 miRNAs had worse survival (p = 0.03). We identified a coordinately regulated miRNA target hub that is over expressed in penile squamous cell carcinoma and associated with lymphovascular invasion.

CONCLUSIONS

Our results provide evidence of a novel multiple miRNA based signature associated with lymph node metastasis and unfavorable prognosis of penile squamous cell carcinoma. The integrated loss of miR-1, miR-101 and miR-204 may predict the formation of metastases in penile cancer at an early stage.