Landscape of germline BRCA1/BRCA2 variants in breast and ovarian cancer in Peru.

Background: There is an increasing amount of data from Latin America on the characterization of BRCA variants; however, there is limited information from Peru. We conducted a retrospective study to describe germline pathogenic/likely pathogenic(P/LP) variants and variants of uncertain/unknown significance (VUS) in the BRCA1 and BRCA2 genes in Peru, in patients with breast and ovarian cancer, candidates for treatment with poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors. Methods: The patients were evaluated during the period 2019-2021. Genomic DNA was isolated from peripheral blood samples and targeted sequencing was performed using the Ampliseq BRCA panel. Genetic variant interpretation was carried out in accordance with the recommendations of the American College of Medical Genetics and ClinVar. During this period, 525 patients (143 with breast cancer and 382 with ovarian cancer) were studied. Results: We found that 14.7% (21/143) of breast cancer patients and 20.7% (79/382) of ovarian cancer patients were carriers of P/LP variants in BRCA1/2. The most frequent pathogenic variants detected in BRCA1 were c.2105dupT (BIC: 2224insT, n=12, 18.75%), c.68_69delAG (BIC: 185delAG, n=6, 9.38%), c.140G>T and c.815_824dupAGCCATGTGG (n=5, 7.81%), while in BRCA2 were c.8023A>G (n=6, 16.67%), c.6024dupG (BIC: 6252insG, n=4, 11.11%), and c.9235delG (BIC: 9463delG, n=3, 8.33%). Regarding VUS, we found that 6.99% (10/143) of breast cancer patients and 7.33% (28/382) of ovarian cancer patients were carriers of a VUS in BRCA1/2. For BRCA1, the most frequent VUS was c.93C>G (n=2), and for BRCA2, c.5465A>T (n=4), c.3101T>C (n=3), c.205C>A and c.437T>C (n=2). Conclusion: We found a frequency of 14.7% germline mutations in breast cancer patients and 20.7% in ovarian cancer patients. The most recurrent mutations were BRCA1 c.2105dupT and BRCA2 c.8023A>G. We found that BRCA2 c.8023A>G, c.6024dupG, and c.9235delG were not previously reported in Peruvian patients. BRCA1 c.2344dupA is a novel mutation that has not been previously reported in any database. The frequency of VUS in our cohort was 7.2%.

The E1a Adenoviral Gene Upregulates the Yamanaka Factors to Induce Partial Cellular Reprogramming.

The induction of pluripotency by enforced expression of different sets of genes in somatic cells has been achieved with reprogramming technologies first described by Yamanaka's group. Methodologies for generating induced pluripotent stem cells are as varied as the combinations of genes used. It has previously been reported that the adenoviral E1a gene can induce the expression of two of the Yamanaka factors (c-Myc and Oct-4) and epigenetic changes. Here, we demonstrate that the E1a-12S over-expression is sufficient to induce pluripotent-like characteristics closely to epiblast stem cells in mouse embryonic fibroblasts through the activation of the pluripotency gene regulatory network. These findings provide not only empirical evidence that the expression of one single factor is sufficient for partial reprogramming but also a potential mechanistic explanation for how viral infection could lead to neoplasia if they are surrounded by the appropriate environment or the right medium, as happens with the tumorogenic niche.

Mesenchymal Stem Cells Delivery in Individuals with Different Pathologies: Multimodal Tracking, Safety and Future Applications.

Due to their ease of isolation and their properties, mesenchymal stem cells (MSCs) have been widely investigated. MSCs have been proved capable of migration towards areas of inflammation, including tumors. Therefore, they have been suggested as vectors to carry therapies, specifically to neoplasias. As most of the individuals joining clinical trials that use MSCs for cancer and other pathologies are carefully recruited and do not suffer from other diseases, here we decided to study the safety and application of iv-injected MSCs in animals simultaneously induced with different inflammatory pathologies (diabetes, wound healing and tumors). We studied this by in vitro and in vivo approaches using different gene reporters (GFP, hNIS, and f-Luc) and non-invasive techniques (PET, BLI, or fluorescence). Our results found that MSCs reached different organs depending on the previously induced pathology. Moreover, we evaluated the property of MSCs to target tumors as vectors to deliver adenoviruses, including the interaction between tumor microenvironment and MSCs on their arrival. Mechanisms such as transdifferentiation, MSC fusion with cells, or paracrine processes after MSCs homing were studied, increasing the knowledge and safety of this new therapy for cancer.

Influence of Sex in the Molecular Characteristics and Outcomes of Malignant Tumors.

BACKGROUND: Sex is frequently underestimated as a prognostic biomarker in cancer. In this study, we evaluated a large cohort of patients and public datasets to determine the influence of sex on clinical outcomes, mutational status, and activation of immune pathways in different types of cancer. METHODS: A cohort of 13,619 Oncosalud-affiliated patients bearing sex-unrelated cancers was followed over a 20-year period. Hazard ratios (HRs) for death were estimated for female vs. male patients for each cancer type and then pooled in a meta-analysis to obtain an overall HR. In addition, the mutational status of the main actionable genes in melanoma (MEL), colorectal cancer (CRC), and lung cancer was compared between sexes. Finally, a gene set enrichment analysis (GSEA) of publicly available data was conducted, to assess differences in immune processes between sexes in MEL, gastric adenocarcinoma (GC), head and neck cancer (HNC), colon cancer (CC), liver cancer (LC), pancreatic cancer (PC), thyroid cancer (TC), and clear renal cell carcinoma (CCRCC). RESULTS: Overall, women had a decreased risk of death (HR = 0.73, CI95: 8%-42%), with improved overall survival (OS) in HNC, leukemia, lung cancer, lymphoma, MEL, multiple myeloma (MM), and non-melanoma skin cancer. Regarding the analysis of actionable mutations, only differences in EGFR alterations were observed (27.7% for men vs. 34.4% for women, p = 0.035). The number of differentially activated immune processes was higher in women with HNC, LC, CC, GC, MEL, PC, and TC and included cellular processes, responses to different stimuli, immune system development, immune response activation, multiorganism processes, and localization of immune cells. Only in CCRCC was a higher activation of immune pathways observed in men. CONCLUSIONS: The study shows an improved survival rate, increased activation of immune system pathways, and an enrichment of EGFR alterations in female patients of our cohort. Enhancement of the immune response in female cancer patients is a phenomenon that should be further explored to improve the efficacy of immunotherapy.

Gold nanoparticle coatings as efficient adenovirus carriers to non-infectable stem cells.

Mesenchymal stem cells (MSCs) are adult pluripotent cells with the plasticity to be converted into different cell types. Their self-renewal capacity, relative ease of isolation, expansion and inherent migration to tumors, make them perfect candidates for cell therapy against cancer. However, MSCs are notoriously refractory to adenoviral infection, mainly because CAR (Coxsackie-Adenovirus Receptor) expression is absent or downregulated. Over the last years, nanoparticles have attracted a great deal of attention as potential vehicle candidates for gene delivery, but with limited effects on their own. Our data showed that the use of positively charged 14 nm gold nanoparticles either functionalized with arginine-glycine-aspartate (RGD) motif or not, increases the efficiency of adenovirus infection in comparison to commercial reagents without altering cell viability or cell phenotype. This system represents a simple, efficient and safe method for the transduction of MSCs, being attractive for cancer gene and cell therapies.

Correction: Gold nanoparticle coatings as efficient adenovirus carriers to non-infectable stem cells.

[This corrects the article DOI: 10.1039/C8RA09088B.].

Distribution of tumor-infiltrating immune cells in glioblastoma.

AIM: Evaluation of features related to infiltrating immune cell level in glioblastoma. METHODS: Tumor-infiltrating lymphocytes (TILs) through H&E staining, and TILs (CD3, CD4, CD8 and CD20) and macrophage (CD68 and CD163) levels through immunohistochemistry were evaluated through digital analysis. RESULTS: CD68 (9.1%), CD163 (2.2%), CD3 (1.6%) and CD8 (1.6%) had the highest density. Higher CD4+ was associated with unmethylated MGMT (p = 0.016). Higher CD8+ was associated with larger tumoral size (p = 0.027). Higher CD163+ was associated with higher age (p = 0.044) and recursive partitioning analysis = 4. Women (p < 0.05), total resection (p < 0.05), MGMT-methylation (p < 0.001), radiotherapy (p < 0.001), chemotherapy (p < 0.001) and lower CD4+ (p < 0.05) were associated with longer overall survival. CONCLUSION: Macrophages are more frequent than TILs. Some subsets are associated with clinical features.

MGMT promoter methylation in Peruvian patients with glioblastoma.

PURPOSE: O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation predicts the outcome and response to alkylating chemotherapy in glioblastoma. The aim of this study is to evaluate the prevalence of MGMT methylation in Peruvian glioblastoma cases. PATIENTS AND METHODS: We evaluated retrospectively 50 cases of resected glioblastoma during the period 2008-2013 at Instituto Nacional de Enfermedades Neoplasicas in Peru. Samples consisted of paraffin embedded and frozen tumour tissue. MGMT-promoter methylation status and the expression level of MGMT gene were evaluated by methylation-specific PCR and real-time PCR, respectively. RESULTS: Unmethylated, methylated and partially methylated statuses were found in 54%, 20% and 26% of paraffin-embedded samples, respectively. Methylation status was confirmed in the Virgen de la Salud Hospital and frozen samples. There was an association between the status of MGMT-promoter methylation and the level of gene expression (p = 0.001). Methylation was associated with increased progression-free survival (p = 0.002) and overall survival (OS) (p < 0.001). CONCLUSION: MGMT-promoter methylation frequency in Peruvian glioblastoma is similar to that reported in other populations and the detection test has been standardised.

Tumor infiltrating lymphocytes in triple negative breast cancer receiving neoadjuvant chemotherapy.

AIM: To determine influence of neoadjuvant-chemotherapy (NAC) over tumor-infiltrating-lymphocytes (TIL) in triple-negative-breast-cancer (TNBC). METHODS: TILs were evaluated in 98 TNBC cases who came to Instituto Nacional de Enfermedades Neoplasicas from 2005 to 2010. Immunohistochemistry staining for CD3, CD4, CD8 and FOXP3 was performed in tissue microarrays (TMA) sections. Evaluation of H/E in full-face and immunohistochemistry in TMA sections was performed in pre and post-NAC samples. STATA software was used and P value < 0.05 was considered statistically significant. RESULTS: Higher TIL evaluated in full-face sections from pre-NAC tumors was associated to pathologic-complete-response (pCR) (P = 0.0251) and outcome (P = 0.0334). TIL evaluated in TMA sections showed low level of agreement with full-face sections (ICC = 0.017-0.20) and was not associated to pCR or outcome. TIL in post-NAC samples were not associated to response or outcome. Post-NAC lesions with pCR had similar TIL levels than those without pCR (P = 0.6331). NAC produced a TIL decrease in full-face sections (P < 0.0001). Percentage of TIL subpopulations was correlated with their absolute counts. Higher counts of CD3, CD4, CD8 and FOXP3 in pre-NAC samples had longer disease-free-survival (DFS). Higher counts of CD3 in pre-NAC samples had longer overall-survival. Higher ratio of CD8/CD4 counts in pre-NAC was associated with pCR. Higher ratio of CD4/FOXP3 counts in pre-NAC was associated with longer DFS. Higher counts of CD4 in post-NAC samples were associated with pCR. CONCLUSION: TIL in pre-NAC full-face sections in TNBC are correlated to longer survival. TIL in full-face differ from TMA sections, absolute count and percentage analysis of TIL subpopulation closely related.

[Glioblastoma: Molecular analysis and its clinical implications]. / Glioblastoma: Análisis molecular y sus implicancias clínicas.

Glioblastoma (GB) is the most common and most lethal primary brain tumor. Epidemiologic information indicate that its incidence is lower in Hispanic race. Surgery is the only curative strategy and has recently introduced new strategies that increase resection rates. The use of concurrent chemotherapy with radiotherapy improves survival of patients but is associated with toxicity. Improved understanding of molecular biology of GB allows the identification of predictive biomarkers of response and prognosis as well as therapeutic targets for the development of new therapeutic strategies. Among biomarkers are currently available 1p /19q codeletion, IDH mutation and O6-methylguanine DNAmethyltransferase promoter methylation. The identification therapeutic targets enables the development of new drugs and their evaluation in clinical trials, but none has been prospectively validated in phase III clinical trials.

Glioblastoma: análisis molecular y sus implicancias clínicas / Glioblastoma: molecular analysis and its clinical implications

El glioblastoma multiforme (GB) es el tumor cerebral primario del sistema nervioso central (SNC) más frecuente y más letal en la edad adulta. La evidencia epidemiológica indica que su incidencia es menor en la raza hispana. El tratamiento quirúrgico es la opción terapéutica preferente. Recientemente se han introducido nuevas estrategias que incrementan el volumen de resección. El uso de quimioterapia y radioterapia concurrentes mejora la supervivencia de los pacientes, aunque se asocia a toxicidad. La mejora en la comprensión de la biología molecular del GB ha permitido la identificación de biomarcadores predictivos de respuesta terapéutica y pronóstico, así como la identificación de dianas terapéuticas que han permitido el desarrollo de nuevas estrategias en el tratamiento de estos tumores. Entre los biomarcadores actualmente disponibles se encuentran la codelección 1p/19q, la mutación de IDH y la metilación del promotor O6- metilguanina DNA-metiltransferasa. La identificación de dianas terapéuticas permite el desarrollo de nuevas drogas y su evaluación posterior en ensayos clínicos, aunque ninguna de ellas ha sido validada prospectivamente en ensayos clínicos de fase III.

Glioblastoma (GB) is the most common and most lethal primary brain tumor. Epidemiologic information indicate that its incidence is lower in Hispanic race. Surgery is the only curative strategy and has recently introduced new strategies that increase resection rates. The use of concurrent chemotherapy with radiotherapy improves survival of patients but is associated with toxicity. Improved understanding of molecular biology of GB allows the identification of predictive biomarkers of response and prognosis as well as therapeutic targets for the development of new therapeutic strategies. Among biomarkers are currently available 1p /19q codeletion, IDH mutation and O6-methylguanine DNAmethyltransferase promoter methylation. The identification therapeutic targets enables the development of new drugs and their evaluation in clinical trials, but none has been prospectively validated in phase III clinical trials.

Prognostic factors for patients with newly diagnosed brain metastasis from breast cancer.

AIM: This retrospective study determined features associated with brain metastasis (BM) in women with breast cancer. PATIENTS & METHODS: A total of 215 initially early breast cancer cases were included. We reviewed files and CT scan images of BM. RESULTS: Median age was 47 years and most of our cases were stage III (58.6%), grade III (62.8%), ER negative (62.3%) and nonluminal (59.1%). Median survival after BM was 4 months. Nonluminal, extracranial disease, time to CNS shorter than 15 months, >three brain lesions and poor breast-graded prognostic assessment and recursive partitioning analysis scores were associated with shorter survival. Adding extracranial disease to breast-graded prognostic assessment score also predicted survival after BM. Radiation response was assessed in 57 patients and response tended to be associated with nonluminal phenotype but not with survival. CONCLUSION: Factors associated with both initial tumor and clinical features at BM time are associated with shorter survival in our Latinas population.

Tissue-derived mesenchymal stromal cells used as vehicles for anti-tumor therapy exert different in vivo effects on migration capacity and tumor growth.

BACKGROUND: Mesenchymal stem cells (MSCs) have been promoted as an attractive option to use as cellular delivery vehicles to carry anti-tumor agents, owing to their ability to home into tumor sites and secrete cytokines. Multiple isolated populations have been described as MSCs, but despite extensive in vitro characterization, little is known about their in vivo behavior.The aim of this study was to investigate the efficacy and efficiency of different MSC lineages derived from five different sources (bone marrow, adipose tissue, epithelial endometrium, stroma endometrium, and amniotic membrane), in order to assess their adequacy for cell-based anti-tumor therapies. Our study shows the crucial importance of understanding the interaction between MSCs and tumor cells, and provides both information and a methodological approach, which could be used to develop safer and more accurate targeted therapeutic applications. METHODS: We first measured the in vivo migration capacity and effect on tumor growth of the different MSCs using two imaging techniques: (i) single-photon emission computed tomography combined with computed tomography (SPECT-CT), using the human sodium iodine symporter gene (hNIS) and (ii) magnetic resonance imaging using superparamagnetic iron oxide. We then sought correlations between these parameters and expression of pluripotency-related or migration-related genes. RESULTS: Our results show that migration of human bone marrow-derived MSCs was significantly reduced and slower than that obtained with the other MSCs assayed and also with human induced pluripotent stem cells (hiPSCs). The qPCR data clearly show that MSCs and hiPSCs exert a very different pluripotency pattern, which correlates with the differences observed in their engraftment capacity and with their effects on tumor growth. CONCLUSION: This study reveals differences in MSC recruitment/migration toward the tumor site and the corresponding effects on tumor growth. Three observations stand out: 1) tracking of the stem cell is essential to check the safety and efficacy of cell therapies; 2) the MSC lineage to be used in the cell therapy needs to be carefully chosen to balance efficacy and safety for a particular tumor type; and 3) different pluripotency and mobility patterns can be linked to the engraftment capacity of the MSCs, and should be checked as part of the clinical characterization of the lineage.

Using living cells to transport therapeutic genes for cancer treatment.

One of the key problems in cancer gene therapy is the inefficient delivery of therapeutic transgenes to tumour sites, after the systemic injection of the viral vector. Hence, new vector discovery is extremely important for the improvement of gene therapy results. Previously, mammalian cells were proposed as new vector systems; however with recent advances in stem cell research this modality makes them more suitable candidates. Tumours are composed of both malignant and benign cells. As "benign" cell types are able to form blood vessels, and stroma, it has been hypothesised that exogenously administrated cells of a different kind would preferentially engraft at the stromal tumour site and could deliver cancer gene therapy vectors to tumours.

Uveal vs. cutaneous melanoma. Origins and causes of the differences.

Melanoma is a malignant tumour derived from melanocytes (dendritic cells originated from the neural crest and capable to produce melanin synthesis) that could be established on the skin or less frequently on the uvea. The cellular origin from both kind of melanoma seems to be the same but the melanocytes migrates to the epithelia for cutaneous melanoma, while for uveal melanoma, they migrate to mesodermic tissues. Despite the common origin, both melanomas show extreme differences in their metastatic potential, clinical response to treatments, immune response and genetic alterations. We will describe some of those differences in this review.