Molecular and immune targets in cutaneous squamous cell carcinoma

Dendritic Poly(l-lysine)-Based Nanoparticle Loading with siDNMT1 to Alleviate Basal Cell Carcinoma Progression by Inhibiting Methylation of AXIN2

Basal cell carcinoma (BCC) is a highly invasive and metastatic non-melanoma skin tumor. Traditional treatments, such as surgery, radiation, and chemotherapy, often result in severe side effects. Recent advances in RNA interference (RNAi) have highlighted its potential in targeting cancer-causing genes. To address the complex pathology of BCC, we developed a multifunctional gene delivery system using benzylthio-modified dendritic polylysine nanoparticles loaded with siDNMT1 (siDNMT1@PDPs). This system exhibits excellent dispersibility, with over 85% of particles measuring between 50 and 80 nm, and high stability, with a zeta potential of +57.10 mV. This design enables efficient penetration into tumor cells and controlled release of siDNMT1 in the tumor microenvironment (TME), thereby improving therapeutic outcomes. Our results demonstrate that siDNMT1@PDPs significantly inhibit tumor progression and metastasis in BCC by reducing AXIN2 promoter methylation, thereby increasing AXIN2 expression. Compared to existing treatments, siDNMT1@PDPs exhibit superior biocompatibility, both in vitro and in vivo, and provide a more targeted and effective therapeutic approach. These findings suggest that siDNMT1@PDPs represent a promising advancement in RNAi-based therapies for BCC, offering potential clinical benefits over current treatment modalities.

PD-L1 Inhibitor Cosibelimab for Cutaneous Squamous Cell Carcinoma: Comprehensive Evaluation of Efficacy, Mechanism, and Clinical Trial Insights

Cutaneous squamous cell carcinoma (CSCC) is one of the most common non-melanoma skin cancers, and particularly challenging to treat in advanced or metastatic stages. Traditional therapies, including chemotherapy and radiation, often result in limited efficacy and severe side effects. Cosibelimab, a fully human monoclonal antibody targeting PD-L1, has emerged as a promising immunotherapy for advanced CSCC. In this review, we evaluate the therapeutic potential of cosibelimab by analyzing its mechanism of action, clinical trial data, and its role compared to other PD-1/PD-L1 inhibitors, such as pembrolizumab and cemiplimab. We synthesized the available preclinical and clinical data on cosibelimab, focusing on published Phase I and II trial results involving 76 patients. Objective response rates (ORRs), progression-free survival (PFS), overall survival (OS), and safety profiles were compared between cosibelimab, pembrolizumab, and cemiplimab. Mechanistic insights into cosibelimab's dual action, including PD-L1 blockade and antibody-dependent cellular cytotoxicity (ADCC), were also explored. Phase II trials demonstrated an ORR of 47.5%, with a median PFS of 12.9 months in advanced CSCC patients. Cosibelimab demonstrated a favorable safety profile, with predominantly mild to moderate adverse events. Comparative analysis with pembrolizumab and cemiplimab showed similar efficacy, although long-term survival data for cosibelimab is still emerging. Given its efficacy and safety, cosibelimab holds promise not only as a monotherapy but also for future exploration in combination regimens and broader oncologic indications. Future trials are required to validate its long-term outcomes, including overall survival, and to explore its use in combination therapies and neoadjuvant/adjuvant settings.

MicroRNA-124 plays an inhibitory role in cutaneous squamous cell carcinoma cells via targeting SNAI2, an immunotherapy determinant

MicroRNAs (miRs) play multiple roles during cutaneous squamous cell carcinoma (CSCC) progression. Previous studies suggest miR-124 could inhibit cancer development in CSCC.

METHODS

Obtained 63 pairs of CSCC and adjacent tissues for analysis. Cultured HaCaT and two CSCC cell lines (A431 and SCL-1) in DMEM (10 % FBS). Transfected cells using Lipofectamine 2000 with various miR-124 mimics, inhibitors, or Snail family transcriptional repressor 2 (SNAI2) expression plasmid. Performed a series of assays, including real-time quantitative PCR, Western blot, CCK8, wound healing, transwell, and luciferase reporter gene assay, to examine the effects of miR-124 on CSCC cells.

RESULTS

An evident downregulation of miR-124 in CSCC tissues, which was related to advanced disease stage and nodal metastasis. Overexpressing miR-124 could reduce the proliferation, migration, and invasion abilities of CSCC cells. It was verified that miR-124 targets the SNAI2 in CSCC cells. Moreover, ectopic expression of SNAI2 rescued the suppressive effects on CSCC cells induced by miR-124 overexpression. Furthermore, miR-124 increased cell sensitivity to cisplatin. Besides, SNAI2 is a critical factor in the immune-related aspects of CSCC and its modulation may influence the response to immunotherapy.

CONCLUSION

We demonstrate that miR-124 inhibits CSCC progression through downregulating SNAI2, and thus it may be a molecular candidate for treating CSCC in the clinic.