Emerging Systemic Therapies for the Management of Penile Cancer

The combination of immune checkpoint inhibitors and antibody-drug conjugates in the treatment of urogenital tumors: a review insights from phase 2 and 3 studies

With the high incidence of urogenital tumors worldwide, urinary system tumors are among the top 10 most common tumors in men, with prostate cancer ranking first and bladder cancer fourth. Patients with resistant urogenital tumors often have poor prognosis. In recent years, researchers have discovered numerous specific cancer antigens, which has led to the development of several new anti-cancer drugs. Using protein analysis techniques, researchers developed immune checkpoint inhibitors (ICIs) and antibody-conjugated drugs (ADCs) for the treatment of advanced urogenital tumors. However, tumor resistance often leads to the failure of monotherapy. Therefore, clinical trials of the combination of ICIs and ADCs have been carried out in numerous centers around the world. This article reviewed phase 2 and 3 clinical studies of ICIs, ADCs, and their combination in the treatment of urogenital tumors to highlight safe and effective methods for selecting individualized therapeutic strategies for patients. ICIs activate the immune system, whereas ADCs link monoclonal antibodies to toxins, which can achieve a synergistic effect when the two drugs are combined. This synergistic effect provides multiple advantages for the treatment of urogenital tumors.

miR-138-5p-mediated HOXD11 promotes cell invasion and metastasis by activating the FN1/MMP2/MMP9 pathway and predicts poor prognosis in penile squamous cell carcinoma

The presence and extent of regional lymph node and distant metastasis are the most fatal prognostic factors in penile squamous cell carcinoma (PSCC). However, the available biomarkers and detailed mechanisms underlying the metastasis of PSCC remain elusive. Here, we explored the expression landscape of HOX genes in twelve paired PSCC tissues, including primary tumors, metastatic lymph nodes and corresponding normal tissues, and highlighted that HOXD11 was indispensable in the progression of PSCC. HOXD11 was upregulated in PSCC cell lines and tumors, especially in metastatic lymph nodes. High HOXD11 expression was associated with aggressive features, such as advanced pN stages, extranodal extension, pelvic lymph node and distant metastasis, and predicted poor survival. Furthermore, tumorigenesis assays demonstrated that knockdown of HOXD11 not only inhibited the capability of cell proliferation, invasion and tumor growth but also reduced the burden of metastatic lymph nodes. Further mechanistic studies indicated that miR-138-5p was a tumor suppressor in PSCC by inhibiting the translation of HOXD11 post-transcriptionally through binding to the 3' untranslated region. Furthermore, HOXD11 activated the transcription of FN1 to decompose the extracellular matrix and to promote epithelial mesenchymal transition-like phenotype metastasis via FN1/MMP2/MMP9 pathways. Our study revealed that HOXD11 is a promising prognostic biomarker and predicts advanced disease with poor outcomes, which could serve as a potential therapeutic target for PSCC.

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.

The Biomarker Potential of Caveolin-1 in Penile Cancer

Various types of human cancers were characterized by an altered expression of epithelial or stromal caveolin-1 (CAV1). However, the clinical significance of CAV1 expression in penile cancer remains largely unknown. Here the expression patterns of CAV1 were analyzed in a retrospective cohort (n=43) of penile squamous cell carcinomas (SCC). Upon penile cancer progression, significantly increased CAV1-levels were determined within the malignant epithelium, whereas within the tumor stroma, namely the fibroblastic tumor compartment harboring activated and/or cancer associated fibroblasts, CAV1 levels significantly decline. Concerning the clinicopathological significance of CAV1 expression in penile cancer as well as respective epithelial-stromal CAV1 distributions, high expression within the tumor cells as well as low expression of CAV1 within the stromal compartment were correlated with decreased overall survival of penile cancer patients. Herein, CAV1 expressions and distributions at advanced penile cancer stages were independent of the immunohistochemically proven tumor protein p53 status. In contrast, less differentiated p16-positive tumor epithelia (indicative for human papilloma virus infection) were characterized by significantly decreased CAV1 levels. Conclusively, we provide further and new evidence that the characteristic shift in stromal‐epithelial CAV1 being functionally relevant to tumor progression even occurs in penile SCC.

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.

Advances in Understanding of Penile Carcinogenesis: The Search for Actionable Targets

Penile cancer (PeCa) is a rare malignancy with potentially devastating effects. Squamous cell carcinoma is the most common variant with distinct precancerous lesions before development into invasive disease. Involvement of the inguinal lymph nodes is the most important prognostic factor in PeCa, and once disease is present outside the groin, prognosis is poor. Metastatic PeCa is challenging to treat and often requires multidisciplinary approaches in management. Due to its rarity, molecular understanding of the disease continues to be limited with most studies based on small, single center series. Thus far, it appears PeCa has diverse mechanisms of carcinogenesis affecting similar molecular pathways. In this review, we evaluate the current landscape of the molecular carcinogenesis of PeCa and explore ongoing research on potential actionable targets of therapy. The emergence of anti-epidermal growth factor receptor (EGFR) and other immunotherapeutic strategies may improve outcomes for PeCa patients.