A Sub-Group of Kidney-Transplant Recipients with Highly Aggressive Squamous Cell Carcinoma Expressing Phosphorylated Serine392p53.

Cutaneous squamous cell carcinomas in kidney-transplant recipients are frequent, with an increasing incidence linked to long immunosuppression durations and exposure to ultraviolet radiation. p53 is at the cornerstone of ultraviolet-induced DNA damage, but the role of p53 post-translational modifications in this context is not yet deciphered. Here, we investigated the phosphorylation status of p53 at Serine 392 in 25 cutaneous squamous cell carcinomas in kidney-transplant recipients, compared with 22 non-transplanted patients. Cutaneous squamous cell carcinomas in transplanted patients occurred after a median period of 19 years of immunosuppression, with a median number of 15 cutaneous squamous cell carcinomas and more aggressive histological and clinical characteristics. There was no significant difference between Ki67, p53, and pSer392p53 expression in the two groups. Using principal component analysis, we identified a cluster of exclusively transplanted patients with a median of 23 years of immunosuppression duration, significantly more aggressive biological characteristics, and higher pSer392p53 expression. pSer392p53 was expressed in the whole tumor, suggesting an early carcinogenic event in the course of prolonged immunosuppression. This high, diffuse pSer392p53 expression, corresponding to a high level of DNA damage, might be useful to identify aggressive cutaneous squamous cell carcinomas in kidney-transplant recipients to treat them more aggressively.

Anti-Angiogenic Tyrosine Kinase Inhibitor-Related Toxicities Among Cancer Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Targeting of angiogenesis has become a major therapeutic approach for the treatment of various advanced cancers. There are many unresolved questions on the toxicity of anti-angiogenic tyrosine kinase inhibitors (TKIs). OBJECTIVE: We performed a meta-analysis to assess the toxicity prevalence of the different anti-angiogenic TKIs among cancer patients and in subpopulations of interest including patients with renal cell carcinoma. PATIENTS AND METHODS: We searched the MEDLINE and Cochrane Library databases to November 2023. Clinical trials were eligible if they set out to report the grade ≥3 toxicities related to one of the seven currently approved anti-angiogenic TKIs as monotherapies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was applied with PROSPERO (CRD42023411946). RESULTS: The 421 eligible studies included a total of 56,895 cancer patients treated with anti-angiogenic TKI monotherapy. Twenty-four different cancer types were identified, mainly renal cell carcinoma (41.9% of the patients). The anti-angiogenic TKI was sorafenib (34.5% of the patients), sunitinib (30.5%), regorafenib (10.7%), pazopanib (9.4%), cabozantinib (7.7%), axitinib (4.3%), and lenvatinib (2.9%). The pooled prevalence of grade 3 and 4 toxicities was 56.1% (95% confidence interval 53.5-58.6), with marked between-study heterogeneity (I2 = 96.8%). Toxicity profiles varied considerably depending on the type of TKI, the cancer type, and the specific patient characteristics. In particular, Asian patients and elderly people had higher prevalences of severe toxicities, with pazopanib being the best-tolerated drug. For patients treated with sunitinib, particularly those with metastatic RCC, there was no significant difference in terms of toxicity according to the regimen schedule. CONCLUSIONS: This meta-analysis highlights the toxicity profiles of anti-angiogenic TKI monotherapies, and thus enables high-level recommendations for the choice of anti-angiogenic TKIs on the basis of the patient's age, ethnicity, comorbidities, and comedications, for personalized treatment.

A Fab of trastuzumab to treat HER2 overexpressing breast cancer brain metastases.

Despite major therapeutic advances for two decades, including the most recently approved anti-HER2 drugs, brain metastatic localizations remain the major cause of death for women with metastatic HER2 breast cancer. The main reason is the limited drug passage of the blood-brain barrier after intravenous injection and the significant efflux of drugs, including monoclocal antibodies, after administration into the cerebrospinal fluid. We hypothesized that this efflux was linked to the presence of a FcRn receptor in the blood-brain barrier. To overcome this efflux, we engineered two Fab fragments of trastuzumab, an anti-HER2 monoclonal antibody, and did a thorough preclinical development for therapeutic translational purpose. We demonstrated the safety and equal efficacy of the Fabs with trastuzumab in vitro, and in vivo using a patient-derived xenograft model of HER2 overexpressing breast cancer. For the pharmacokinetic studies of intra-cerebrospinal fluid administration, we implemented original rat models with catheter implanted into the cisterna magna. After intraventricular administration in rats, we demonstrated that the brain-to-blood efflux of Fab was up to 10 times lower than for trastuzumab, associated with a two-fold higher brain penetration compared to trastuzumab. This Fab, capable of significantly reducing brain-to-blood efflux and enhancing brain penetration after intra-cerebrospinal fluid injection, could thus be a new and original effective drug in the treatment of HER2 breast cancer brain metastases, which will be demonstrated by a phase I clinical trial dedicated to women in resort situations.

PROM2 overexpression induces metastatic potential through epithelial-to-mesenchymal transition and ferroptosis resistance in human cancers.

INTRODUCTION: Despite considerable therapeutic advances in the last 20 years, metastatic cancers remain a major cause of death. We previously identified prominin-2 (PROM2) as a biomarker predictive of distant metastases and decreased survival, thus providing a promising bio-target. In this translational study, we set out to decipher the biological roles of PROM2 during the metastatic process and resistance to cell death, in particular for metastatic melanoma. METHODS AND RESULTS: Methods and results: We demonstrated that PROM2 overexpression was closely linked to an increased metastatic potential through the increase of epithelial-to-mesenchymal transition (EMT) marker expression and ferroptosis resistance. This was also found in renal cell carcinoma and triple negative breast cancer patient-derived xenograft models. Using an oligonucleotide anti-sense anti-PROM2, we efficaciously decreased PROM2 expression and prevented metastases in melanoma xenografts. We also demonstrated that PROM2 was implicated in an aggravation loop, contributing to increase the metastatic burden both in murine metastatic models and in patients with metastatic melanoma. The metastatic burden is closely linked to PROM2 expression through the expression of EMT markers and ferroptosis cell death resistance in a deterioration loop. CONCLUSION: Our results open the way for further studies using PROM2 as a bio-target in resort situations in human metastatic melanoma and also in other cancer types.