19 research outputs found
A Rare Nasopharyngeal Presentation of Amyloidosis
Amyloidosis is a heterogeneous group of diseases characterized by the extracellular deposition of insoluble proteins whose pathogenesis is not yet fully understood. The deposition of amyloid proteins can be systemic or localized, idiopathic or related to systemic diseases, mostly multiple myeloma or chronic inflammatory diseases. Localized head and neck amyloidosis is a rare entity, mainly involving the larynx. Given the rarity of the disease and the absence of a lasting follow-up protocol, there is no standard treatment defined for localized amyloidosis. We report a rare case of localized nasopharyngeal amyloidosis, treated with complete transoral resection and confirmed by histological examination
A Strange Association Between A Rectum- Infiltrating / Metastatic Dedifferentiated Chordoma And Schmidt's Syndrome
n/
A non-dividing cell population with high pyruvate dehydrogenase kinase activity regulates metabolic heterogeneity and tumorigenesis in the intestine
DNA damage response and repair genes in advanced bone and soft tissue sarcomas: An 8-gene signature as a candidate predictive biomarker of response to trabectedin and olaparib combination
Parp1 inhibitor and trabectedin combination does not increase tumor mutational burden in advanced sarcomas—a preclinical and translational study
SIMPLE SUMMARY: Immunotherapy has revolutionized cancer treatment, but not for all tumor types. Indeed, sarcomas are considered “immune-cold” tumors, which are relatively unresponsive to immunotherapy. One strategy to potentiate immunotherapy efficacy is to increase tumor immunogenicity, for instance by boosting the number of candidate targets (neoantigens) to be recognized by the immune system. Tumor mutational burden indicates the number of somatic mutations identified in the tumor and normalized per megabase. Tumor mutational burden is considered as an acceptable, measurable surrogate of tumor neoantigens. Here, we explored whether the combination of two DNA-damaging agents, trabectedin and olaparib, could increase tumor mutational burden in sarcomas, to prime subsequent immunotherapy. We found no variation in tumor mutational burden after trabectedin + olaparib in preclinical and clinical samples. Therefore, other aspects should be considered to increase sarcoma immunogenicity, by exploiting different pathways such as the potential modulation of the tumor microenvironment induced by trabectedin + olaparib. ABSTRACT: Drug-induced tumor mutational burden (TMB) may contribute to unleashing the immune response in relatively “immune-cold” tumors, such as sarcomas. We previously showed that PARP1 inhibition perpetuates the DNA damage induced by the chemotherapeutic agent trabectedin in both preclinical models and sarcoma patients. In the present work, we explored acquired genetic changes in DNA repair genes, mutational signatures, and TMB in a translational platform composed of cell lines, xenografts, and tumor samples from patients treated with trabectedin and olaparib combination, compared to cells treated with temozolomide, an alkylating agent that induces hypermutation. Whole-exome and targeted panel sequencing data analyses revealed that three cycles of trabectedin and olaparib combination neither affected the mutational profiles, DNA repair gene status, or copy number alterations, nor increased TMB both in homologous recombinant-defective and proficient cells or in xenografts. Moreover, TMB was not increased in tumor specimens derived from trabectedin- and olaparib-treated patients (5–6 cycles) when compared to pre-treatment biopsies. Conversely, repeated treatments with temozolomide induced a massive TMB increase in the SJSA-1 osteosarcoma model. In conclusion, a trabectedin and olaparib combination did not show mutagenic effects and is unlikely to prime subsequent immune-therapeutic interventions based on TMB increase. On the other hand, these findings are reassuring in the increasing warning of treatment-induced hematologic malignancies correlated to PARP1 inhibitor use
Recommended from our members
PIK3R1W624R Is an Actionable Mutation in High Grade Serous Ovarian Carcinoma.
Identifying cancer drivers and actionable mutations is critical for precision oncology. In epithelial ovarian cancer (EOC) the majority of mutations lack biological or clinical validation. We fully characterized 43 lines of Patient-Derived Xenografts (PDXs) and performed copy number analysis and whole exome sequencing of 12 lines derived from naïve, high grade EOCs. Pyrosequencing allowed quantifying mutations in the source tumours. Drug response was assayed on PDX Derived Tumour Cells (PDTCs) and in vivo on PDXs. We identified a PIK3R1W624R variant in PDXs from a high grade serous EOC. Allele frequencies of PIK3R1W624R in all the passaged PDXs and in samples of the source tumour suggested that it was truncal and thus possibly a driver mutation. After inconclusive results in silico analyses, PDTCs and PDXs allowed the showing actionability of PIK3R1W624R and addiction of PIK3R1W624R carrying cells to inhibitors of the PI3K/AKT/mTOR pathway. It is noteworthy that PIK3R1 encodes the p85α regulatory subunit of PI3K, that is very rarely mutated in EOC. The PIK3R1W624R mutation is located in the cSH2 domain of the p85α that has never been involved in oncogenesis. These data show that patient-derived models are irreplaceable in their role of unveiling unpredicted driver and actionable variants in advanced ovarian cancer
How Risk Factors Affect Head and Neck Squamous Cell Carcinoma (HNSCC) Tumor Immune Microenvironment (TIME): Their Influence on Immune Escape Mechanisms and Immunotherapy Strategy
Most head and neck squamous cell carcinomas (HNSCCs) are caused by lifestyle, such as cigarette smoking, or by viruses, such as human papillomavirus (HPV) and Epstein–Barr virus (EBV). HNSCC remains a clinical challenge, notwithstanding the improvements observed in the past years, involving surgery, radiotherapy, and chemotherapy. Recurrent/metastatic (R/M) disease represents an unmet clinical need. Immunotherapy has improved the prognosis of a small proportion of these patients, but most still do not benefit. In the last decade, several preclinical and clinical studies have explored the HNSCC tumor immune microenvironment (TIME), identifying important differences between smoking-associated and virus-associated HNSCCs. This review aims to present how different etiologies affect the HNSCC TIME, affecting immune escape mechanisms and sensitivity to immunotherapy
Caveolin 1 expression independently predicts shorter survival in oligodendrogliomas.
Caveolin 1 (cav-1) is the basic component of the flask-shaped membrane microdomains known as caveolae that are involved in various cell functions. Caveolin 1 can be overexpressed in tumors,suggesting a proneoplastic role, or it can be downregulated. We previously reported that cav-1 expression increases with tumor grade in astrocytomas. Here, we studied cav-1 immunoreactivity in brain umors with an oligodendroglial component to determine the prognostic value of cav-1 expression and to correlate it with 1p/19q deletions. Fifty-four oligodendrogliomas, 26 mixed oligoastrocytomas,and 7 glioblastomas with an oligodendroglial component were assessed for cav-1 expression by immunohistochemistry and for 1p/19q status by fluorescence in situ hybridization. Caveolin-1 was detected in a minority of cases (22%) and was associated mostly with Grade III mixed oligoastrocytomas and glioblastomas with anoligodendroglial component; cav-1 expression was significantly correlated with the absence of a 1p/19q deletion (p = 0.0002). In the 63 cases in which survival data were available, cav-1 expression was also significantly associated with shorter survivals, whereas 1p/19q deletion was associated with longer survivals. Among high-grade tumors, cav-1 expression was the only factor that retained a statistical significance after multivariate analysis for the prediction ofa short survival (p G 0.015). These data are the first evidence that cav-1 immunohistochemistry is an independent prognostic marker in tumors with an oligodendroglial component regardless of the 1p/19q status.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe