Structural and functional insights into GSDMB isoforms complex roles in pathogenesis

SHADSGasdermins (GSDMs) have garnered significant scientific interest due to their protective and detrimental roles in innate immunity, host defense, inflammation, and cancer alongside with other pathologies. While GSDMs are mostly recognized as key effectors of a lytic type of pro-inflammatory cell death known as pyroptosis, they do also take part in other cell death processes (NETosis, secondary necrosis, or apoptosis) and exhibit cell-death independent functions depending on the cellular context. Among GSDMs, Gasdermin B (GSDMB) pyroptotic capacity has been a subject of conflicting findings in scientific literature even when its processing, and subsequent activation, by Granzyme A (GZMA) was decoded. Nevertheless, recent groundbreaking publications have shed light on the crucial role of alternative splicing in determining the pyroptotic capacity of GSDMB isoforms, which depends on the presence of exon 6-derived elements. This comprehensive review pays attention to the relevant structural differences among recently crystalized GSDMB isoforms. As a novelty, the structural aspects governing GSDMB isoform susceptibility to GZMA-mediated activation have been investigated. By elucidating the complex roles of GSDMB isoforms, this review aims to deepen the understanding of this multifunctional player and its potential implications in disease pathogenesis and therapeutic interventions. [Figure: see text].

RUNAT-BI: A Ruthenium(III) Complex as a Selective Anti-Tumor Drug Candidate against Highly Aggressive Cancer Cell Lines

Ruthenium compounds have demonstrated promising activity in different cancer types, overcoming several limitations of platinum-based drugs, yet their global structure-activity is still under debate. We analyzed the activity of Runat-BI, a racemic Ru(III) compound, and of one of its isomers in eight tumor cell lines of breast, colon and gastric cancer as well as in a non-tumoral control. Runat-BI was prepared with 2,2'-biimidazole and dissolved in polyethylene glycol. We performed assays of time- and dose-dependent viability, migration, proliferation, and expression of pro- and antiapoptotic genes. Moreover, we studied the growth rate and cell doubling time to correlate it with the apoptotic effect of Runat-BI. As a racemic mixture, Runat-BI caused a significant reduction in the viability and migration of three cancer cell lines from colon, gastric and breast cancer, all of which displayed fast proliferation rates. This compound also demonstrated selectivity between tumor and non-tumor lines and increased proapoptotic gene expression. However, the isolated isomer did not show any effect. Racemic Runat-BI is a potential drug candidate for treatment of highly aggressive tumors. Further studies should be addressed at evaluating the role of the other isomer, for a more precise understanding of its antitumoral potential and mechanism of action.

Intratumor genetic heterogeneity and clonal evolution to decode endometrial cancer progression

Analyzing different tumor regions by next generation sequencing allows the assessment of intratumor genetic heterogeneity (ITGH), a phenomenon that has been studied widely in some tumor types but has been less well explored in endometrial carcinoma (EC). In this study, we sought to characterize the spatial and temporal heterogeneity of 9 different ECs using whole-exome sequencing, and by performing targeted sequencing validation of the 42 primary tumor regions and 30 metastatic samples analyzed. In addition, copy number alterations of serous carcinomas were assessed by comparative genomic hybridization arrays. From the somatic mutations, identified by whole-exome sequencing, 532 were validated by targeted sequencing. Based on these data, the phylogenetic tree reconstructed for each case allowed us to establish the tumors’ evolution and correlate this to tumor progression, prognosis, and the presence of recurrent disease. Moreover, we studied the genetic landscape of an ambiguous EC and the molecular profile obtained was used to guide the selection of a potential personalized therapy for this patient, which was subsequently validated by preclinical testing in patient-derived xenograft models. Overall, our study reveals the impact of analyzing different tumor regions to decipher the ITGH in ECs, which could help make the best treatment decision.

Predictive Role of Leptin Receptor (Ob-R) Overexpression in Patients with Early Breast Cancer Receiving Neoadjuvant Systemic Treatment

The primary aim of this retrospective study was to investigate the correlation between the immunohistochemical expression of Ob-R (leptin receptor) with pCR (pathological complete response) in early breast cancer patients receiving neoadjuvant systemic treatment (NST). A total of 100 women with breast cancer receiving NST (2017-2020) followed by surgical resection were retrospectively obtained. Demographic parameters and clinicopathological factors (e.g., treatment modalities, immunohistochemistry (IHC), and cancer subtype) were obtained from the patient's clinical records. In the analyzed breast cancer cohort, high expression of Ob-R was found in 52% of tumors and there was a significantly higher incidence in the HER2+ and TNBC subgroups. Overall, a significantly greater percentage of patients with Ob-R positive tumors achieved pCR compared with Ob-R negative patients (57.7% vs. 27.1%; p = 0.002). This result was observed in most breast cancer subtypes. In patients with HER2+ breast cancer, there was no difference in Ob-R expression in relation to the HR status. Ob-R cell positivity was significantly higher in younger breast cancer patients (p = 0.008), those who were premenopausal (p = 0.011), and in those with a BMI > 25 kg/m² (p = 0.019). A significantly greater percentage of early breast cancer patients with Ob-R positive tumors achieved pCR compared with Ob-R negative patients. Furthermore, breast cancer patients with positive Ob-R expression were significantly younger than those with negative Ob-R expression. This association was not explained by differences in BMI between young and old patients.

miRNA Expression Analysis: Cell Lines HCC1500 and HCC1937 as Models for Breast Cancer in Young Women and the miR-23a as a Poor Prognostic Biomarker

PURPOSE

The study of breast cancer nearly always involves patients close to menopause or older. Therefore, young patients are mostly underrepresented. Our aim in this study was to demonstrate biological differences in breast cancer of young people using as a model available cell lines derived from people with breast cancer younger than 35 years.

METHODS

Global miRNA expression was analyzed in breast cancer cells from young (HCC1500, HCC1937) and old patients (MCF-7, MDA-MB-231, HCC1806, and MDA-MB-468). In addition, it was compared with same type of results from patients.

RESULTS

We observed a differential profile for 155 miRNAs between young and older cell lines. We identified a set of 24 miRNA associated with aggressiveness that were regulating pluripotency of stem cell-related pathways. Combining the miRNA expression data from cell lines and breast cancer patients, 132 miRNAs were differently expressed between young and old samples, most of them previously found in cell lines. MiR-23a-downregulation was also associated with poor survival in young patients.

CONCLUSIONS

Our results suggest that HCC1500 and HCC1937 cell lines could be suitable cellular models for breast cancer affecting young women. The miR-23a-downregulation could have a potential role as a poor prognosis biomarker in this age group.

Insight updating of the molecular hallmarks in ovarian carcinoma

Background and purpose

Ovarian cancer (OC) is the deadliest gynaecologic cancer characterised by a high heterogeneity not only at the clinical point of view but also at the molecular level. This review focuses on the new insights about the OC molecular classification.

Materials and methods

We performed a bibliographic search for different indexed articles focused on the new molecular classification of OC. All of them have been published in PubMed and included information about the most frequent molecular alterations in OC confirmed by omics approaches. In addition, we have extracted information about the role of liquid biopsy in the OC diagnosis and prognosis.

Results

New molecular insights into OC have allowed novel clinical entities to be defined. Among OC, high-grade serous ovarian carcinoma (HGSOC) which is the most common OC is characterised by omics approaches, mutations in TP53 and in other genes involved in the homologous recombination repair, especially BRCA1/2. Recent studies in HGSOC have allowed a new molecular classification in subgroups according to their mutational, transcriptional, methylation and copy number variation signatures with a real impact in the characterisation of new therapeutic targets for OC to be defined. Furthermore, despite the intrinsic intra-tumour heterogeneity, the advances in next generation sequencing (NGS) analyses of ascetic liquid from OC have opened new ways for its characterisation and treatment.

Conclusions

The advances in genomic approaches have been used for the identification of new molecular profiling techniques which define OC subgroups and has supposed advances in the diagnosis and in the personalised treatment of OC.

•

Classification of ovarian cancer regarding to widespread genetic and genomic data.

•

Highlighted role of p53 and BRCA1/2 in ovarian cancer for diagnosis and treatment.

•

Intra-tumour genetic heterogeneity in ovarian cancer.

•

Useful of liquid biopsy study in ovarian cancer diagnosis.

Genomic Profiling of Uterine Aspirates and cfDNA as an Integrative Liquid Biopsy Strategy in Endometrial Cancer

The incidence and mortality of endometrial cancer (EC) have risen in recent years, hence more precise management is needed. Therefore, we combined different types of liquid biopsies to better characterize the genetic landscape of EC in a non-invasive and dynamic manner. Uterine aspirates (UAs) from 60 patients with EC were obtained during surgery and analyzed by next-generation sequencing (NGS). Blood samples, collected at surgery, were used for cell-free DNA (cfDNA) and circulating tumor cell (CTC) analyses. Finally, personalized therapies were tested in patient-derived xenografts (PDXs) generated from the UAs. NGS analyses revealed the presence of genetic alterations in 93% of the tumors. Circulating tumor DNA (ctDNA) was present in 41.2% of cases, mainly in patients with high-risk tumors, thus indicating a clear association with a more aggressive disease. Accordingly, the results obtained during the post-surgery follow-up indicated the presence of ctDNA in three patients with progressive disease. Moreover, 38.9% of patients were positive for CTCs at surgery. Finally, the efficacy of targeted therapies based on the UA-specific mutational landscape was demonstrated in PDX models. Our study indicates the potential clinical applicability of a personalized strategy based on a combination of different liquid biopsies to characterize and monitor tumor evolution, and to identify targeted therapies.

Breast Cancer in Very Young Patients in a Spanish Cohort: Age as an Independent Bad Prognostic Indicator

Purpose:

Breast cancer (BC) in very young women (BCVY) is more aggressive than in older women. The purpose of this study was to evaluate the relevance of a range of clinico-pathological factors in the prognosis of BCVY patients.

Methods:

We retrospectively analyzed 258 patients diagnosed with BCVY at our hospital from 1998 to 2014; the control group comprised 101 older patients with BC. We correlated clinicopathological factors, treatments, relapse and exitus with age and with previously published miRNA expression data.

Results:

We identified some significant differences in risk factors between BCVY and older patients. The age at menarche, number of pregnancies, and age at first pregnancy were lower in the BCVY group and had a greater probability of recurrence and death in all cases. Lymph node-positive patients in the BCVY group are associated with a worse prognosis (P = .02), an immunohistochemical HER2⁺ subtype, and disease relapse (P = .03). Moreover, there was a shorter time between diagnosis and first relapse in BCVY patients compared with controls, and they were more likely to die from the disease (P = .002). Finally, from our panel of miRNAs deregulated in BC, reduced miR-30c expression was associated with more aggressive BC in very young patients, lower overall survival, and with axillary lymph node metastases.

Conclusions:

Patient age and axillary lymph node status post-surgery are independent and significant predictors of distant disease-free survival, local recurrence-free survival, and overall survival. The HER2⁺ subtype and lower miR-30c expression are related to poor prognosis in lymph node-positive young BC patients.

Methylation deregulation of miRNA promoters identifies miR124-2 as a survival biomarker in Breast Cancer in very young women

MiRNAs are part of the epigenetic machinery, and are also epigenetically modified by DNA methylation. MiRNAs regulate expression of different genes, so any alteration in their methylation status may affect their expression. We aimed to identify methylation differences in miRNA encoding genes in breast cancer affecting women under 35 years old (BCVY), in order to identify potential biomarkers in these patients. In Illumina Infinium MethylationEPIC BeadChip samples (metEPICVal), we analysed the methylation of 9,961 CpG site regulators of miRNA-encoding genes present in the array. We identified 193 differentially methylated CpG sites in BCVY (p-value < 0.05 and methylation differences ±0.1) that regulated 83 unique miRNA encoding genes. We validated 10 CpG sites using two independent datasets based on Infinium Human Methylation 450k array. We tested gene expression of miRNAs with differential methylation in BCVY in a meta-analysis using The Cancer Genome Atlas (TCGA), Clariom D and Affymetrix datasets. Five miRNAs (miR-9, miR-124-2, miR-184, miR-551b and miR-196a-1) were differently expressed (FDR p-value < 0.01). Finally, only miR-124-2 shows a significantly different gene expression by quantitative real-time PCR. MiR-124-hypomethylation presents significantly better survival rates for older patients as opposed to the worse prognosis observed in BCVY, identifying it as a potential specific survival biomarker in BCVY.

Sex-specific genetic effects associated with pigmentation, sensitivity to sunlight, and melanoma in a population of Spanish origin

BACKGROUND

Human pigmentation is a polygenic quantitative trait with high heritability. In addition to genetic factors, it has been shown that pigmentation can be modulated by oestrogens and androgens via up- or down-regulation of melanin synthesis. Our aim was to identify possible sex differences in pigmentation phenotype as well as in melanoma association in a melanoma case-control population of Spanish origin.

METHODS

Five hundred and ninety-nine females (316 melanoma cases and 283 controls) and 458 males (234 melanoma cases and 224 controls) were analysed. We genotyped 363 polymorphisms (single nucleotide polymorphisms (SNPs)) from 65 pigmentation gene regions.

RESULTS

When samples were stratified by sex, we observed more SNPs associated with dark pigmentation and good sun tolerance in females than in males (107 versus 75; P = 2.32 × 10(-6)), who were instead associated with light pigmentation and poor sun tolerance. Furthermore, six SNPs in TYR, SILV/CDK2, GPR143, and F2RL1 showed strong differences in melanoma risk by sex (P < 0.01).

CONCLUSIONS

We demonstrate that these genetic variants are important for pigmentation as well as for melanoma risk, and also provide suggestive evidence for potential differences in genetic effects by sex.

MicroRNA profile in very young women with breast cancer

Background

Breast cancer is rarely diagnosed in very young women (35years old or younger), and it often presents with distinct clinical-pathological features related to a more aggressive phenotype and worse prognosis when diagnosed at this early age. A pending question is whether breast cancer in very young women arises from the deregulation of different underlying mechanisms, something that will make this disease an entity differentiated from breast cancer diagnosed in older patients.

Methods

We performed a comprehensive study of miRNA expression using miRNA Affymetrix2.0 array on paraffin-embedded tumour tissue of 42 breast cancer patients 35 years old or younger, 17 patients between 45 and 65 years old and 29 older than 65 years. Data were statistically analyzed by t-test and a hierarchical clustering via average linkage method was conducted. Results were validated by qRT-PCR. Putative targeted pathways were obtained using DIANA miRPath online software.

Results

The results show a differential and unique miRNA expression profile of 121 miRNAs (p-value <0.05), 96 of those with a FDR-value <0.05. Hierarchical clustering grouped the samples according to their age, but not by subtype nor by tumour characteristics. We were able to validate by qRT-PCR differences in the expression of 6 miRNAs: miR-1228*, miR-3196, miR-1275, miR-92b, miR-139 and miR-1207. Moreover, all of the miRNAs maintained the expression trend. The validated miRNAs pointed out pathways related to cell motility, invasion and proliferation.

Conclusions

The study suggests that breast cancer in very young women appears as a distinct molecular signature. To our knowledge, this is the first time that a validated microRNA profile, distinctive to breast cancer in very young women, has been presented. The miRNA signature may be relevant to open an important field of research in order to elucidate the underlying mechanism in this particular disease, which in a more clinical setting, could potentially help to identify therapeutic targets in this particular set of patients.