Circadian Clock Gene bmal1 Acts as a Tumor Suppressor Gene in a Mice Model of Human Glioblastoma.

Glioblastomas derived from malignant astrocytes are the most common primary tumors of the central nervous system in humans, exhibiting very bad prognosis. Treatment with surgery, radiotherapy, and chemotherapy (mainly using temozolomide), generates as much one-year survival. The circadian clock controls different aspects of tumor development, and its role in GBM is beginning to be explored. Here, the role of the canonic circadian clock gene bmal1 was studied in vivo in a nude mice model bearing human GBMs from LN229 cells xenografted orthotopically in the dorsal striatum. For that aim, a bmal1 knock-down was generated in LN229 cells by CRISPR/Cas9 gene editing tool, and tumor progression was followed in male mice by measuring survival, tumor growth, cell proliferation and prognosis with CD44 marker, as well as astrocyte activation in the tumor microenvironment with GFAP and nestin markers. Disruption of bmal1 in the tumor decreased survival, increased tumor growth and CD44 expression, worsened motor performance, as well as increased GFAP expression in astrocytes at tumor microenvironment. In addition, survival and tumor progression was not affected in mice bearing LN229 wild type GBM that underwent circadian disruption by constant light, as compared to mice synchronized to 12:12 light-dark cycles. These results consistently demonstrate in an in vivo orthotopic model of human GBM, that bmal1 has a key role as a tumor suppressor gene regulating GBM progression.

Genetic variations in tumor-suppressor miRNA-encoding genes and their target genes: focus on breast cancer development and possible therapeutic strategies.

MicroRNAs (miRNAs) negatively affect gene expression by binding to their specific mRNAs resulting in either mRNA destruction or translational repression. The aberrant expression of various miRNAs has been associated with a number of human cancer. Oncogenic or tumor-suppressor miRNAs regulate a variety of pathways involved in the development of breast cancer (BC), including cell proliferation, apoptosis, metastasis, cancer recurrence, and chemoresistance. Variations in miRNA-encoding genes and their target genes lead to dysregulated gene expression resulting in the development and progression of BC. The various therapeutic approaches to treat the disease include chemotherapy, radiation therapy, surgical removal, hormone therapy, chemotherapy, and targeted biological therapy. The purpose of the current review is to explore the genetic variations in tumor-suppressor miRNA-encoding genes and their target genes in association with the disease development and prognosis. The therapeutic interventions targeting the variants for better disease outcomes have also been discussed.

KMT2 (MLL) family of methyltransferases in head and neck squamous cell carcinoma: A systematic review.

BACKGROUND: The involvement of the KMT2 methyltransferase family in the pathogenesis of head and neck squamous cell carcinoma (HNSCC) remains elusive. METHOD: This study adhered to the PRISMA guidelines, employing a search strategy in the LIVIVO, PubMed, Scopus, Embase, Web of Science, and Google Scholar databases. The methodological quality of the studies was assessed by the Joanna Briggs Institute. RESULTS: A total of 33 studies involving 4294 individuals with HNSCC were included in this review. The most important alteration was the high mutational frequency in the KMT2C and KMT2D genes, with reported co-occurrence. The expression of the KMT2D gene exhibited considerable heterogeneity across the studies, while limited data was available for the remaining genes. CONCLUSIONS: KMT2C and KMT2D genes seem to have tumor suppressor activities, with involvement of cell cycle inhibitors, regulating different pathways that can lead to tumor progression, disease aggressiveness, and DNA damage accumulation.

Ribosomal S6 kinase 4 (RSK4) tumor suppressor gene promoter methylation status in ovarian cancer.

BACKGROUND: Previously, we reported lower RSK4 mRNA and protein levels in malignant ovarian tumors compared to normal and benign ovarian tissues. Also, we observed a significant inverse correlation between the advanced ovarian cancer stages and RSK4 mRNA levels. We did not investigate the mechanisms involved in RSK4-reduced expression in ovarian cancer. Thus, this study investigates whether RSK4 promoter methylation in ovarian cancer tissues is responsible for its low expression. Additionally, the reactivation of RSK4 expression and its effect was studied in ovarian cancer cell lines. METHODS AND RESULTS: RSK4 promoter methylation percentage in malignant and benign ovarian tumors and normal ovary tissues was determined by combined bisulfite restriction analysis. The reactivation of RSK4 expression by decitabine treatment was studied in OVCAR3, SKOV3, TOV-112D, and TOV-21G cells by Western blotting. Cell proliferation was determined by XTT. A significantly high methylation percentage of the RSK4 promoter was observed among malignant and benign ovarian tumors but not in normal ovarian tissue. RSK4 promoter methylation was not associated with age, histological subtype, or stages of ovarian cancer. RSK4 promoter methylation correlates weakly but not significantly with RSK4 protein expression. No correlation was shown between RSK4 methylation and RSK4 mRNA expression. Decitabine induces RSK4 reactivation in all cell lines. However, cell proliferation was reduced only in TOV-112D cells. CONCLUSION: These data indicate that although RSK4 promoter methylation is increased in malignant ovarian tumors, this mechanism is unlikely to regulate its expression in ovarian cancer. RSK4 reactivation reduced cell proliferation only in the endometroid histological subtype.

MiRNAs in Hematopoiesis and Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common kind of pediatric cancer. Although the cure rates in ALL have significantly increased in developed countries, still 15-20% of patients relapse, with even higher rates in developing countries. The role of non-coding RNA genes as microRNAs (miRNAs) has gained interest from researchers in regard to improving our knowledge of the molecular mechanisms underlying ALL development, as well as identifying biomarkers with clinical relevance. Despite the wide heterogeneity reveled in miRNA studies in ALL, consistent findings give us confidence that miRNAs could be useful to discriminate between leukemia linages, immunophenotypes, molecular groups, high-risk-for-relapse groups, and poor/good responders to chemotherapy. For instance, miR-125b has been associated with prognosis and chemoresistance in ALL, miR-21 has an oncogenic role in lymphoid malignancies, and the miR-181 family can act either as a oncomiR or tumor suppressor in several hematological malignancies. However, few of these studies have explored the molecular interplay between miRNAs and their targeted genes. This review aims to state the different ways in which miRNAs could be involved in ALL and their clinical implications.

Role of MicroRNA-7 (MiR-7) in Cancer Physiopathology.

miRNAs are non-coding RNA sequences of approximately 22 nucleotides that interact with genes by inhibiting their translation through binding to their 3' or 5' UTR regions. Following their discovery, the role they play in the development of various pathologies, particularly cancer, has been studied. In this context, miR-7 is described as an important factor in the development of cancer because of its role as a tumor suppressor, regulating a large number of genes involved in the development and progression of cancer. Recent data support the function of miR-7 as a prognostic biomarker in cancer, and miR-7 has been proposed as a strategy in cancer therapy. In this work, the role of miR-7 in various types of cancer is reviewed, illustrating its regulation, direct targets, and effects, as well as its possible relationship to the clinical outcome of cancer patients.

Caracterización molecular de pacientes con cáncer colorrectal / Molecular characterization of colorectal cancer patients

Introducción. El cáncer colorrectal tiene una alta incidencia en la población mundial. Diversas vías moleculares están involucradas en su desarrollo, entre ellas, la inestabilidad cromosómica, la inestabilidad microsatelital y la epigenética. Objetivo. Hacer la caracterización molecular de 44 individuos con cáncer colorrectal esporádico. Materiales y métodos. El análisis de mutaciones en los genes APC, KRAS, TP53 y BRAF se hizo mediante secuenciación de Sanger; la inestabilidad microsatelital se determinó mediante electroforesis capilar utilizando cinco marcadores de repetición corta en tándem (Short Tandem Repeat) y el estado de metilación del promotor del gen MLH1 se hizo con la técnica MS-PCR (Methylation-Specific PCR). Resultados. La frecuencia de mutación de los genes APC, KRAS y TP53 fue del 18,1, 25 y 4,5 %, respectivamente; las mutaciones detectadas se localizaron con mayor frecuencia en el colon derecho. La frecuencia de inestabilidad microsatelital fue del 27,2 % y el 73,1 % en los tumores con metilación en el gen MHL1, y el 91,6 % de los tumores con inestabilidad microsatelital presentaba metilación en el gen MLH1. En el grupo de tumores con estabilidad microsatelital, las mutaciones en los genes APC, KRAS y TP53 fueron más frecuentes que en el grupo de tumores con inestabilidad microsatelital. La metilación del gen MLH1 fue la alteración más predominante. Conclusiones. En los pacientes con cáncer colorrectal evaluados se demostró la presencia de alteraciones moleculares en las diferentes vías genéticas, las cuales son comunes en su carcinogénesis. Los pacientes presentaron un perfil de mutaciones diferente al de otras poblaciones. Los hallazgos obtenidos en este estudio confirman la heterogeneidad molecular descrita en el desarrollo del cáncer colorrectal.

Introduction: Colorectal cancer has a high incidence in the world population. Different molecular pathways, such as chromosomal instability, microsatellite instability, and epigenetics are involved in its development. Objective: To perform molecular characterization in 44 individuals with sporadic colorectal cancer. Materials and methods: We conducted mutation analyses of the APC, KRAS, TP53 y BRAF genes using Sanger sequencing techniques; microsatellite instability was determined by capillary electrophoresis with five STR genetic markers while the methylation status of the MHL1 promotor gene was analyzed using methylation-specific PCR. Results: APC, KRAS, and TP53 genes mutation frequency was 18.1%, 25%, and 4.5%, respectively; the somatic mutations detected were located more frequently in the right colon. The frequency of microsatellite instability was 27.2% and 73.1% of the tumors had the MHL1 gene methylated while 91.6% of microsatellite instability-positive tumors had the methylated MLH1 gene. The mutation profile of microsatellite stability tumors APC, KRAS, and TP53 genes was more frequent than in the microsatellite instability-positive tumors. The methylation of the MLH1 gene was the most predominant molecular alteration. Conclusions: We identified molecular alterations in different genetic pathways of the colorectal cancer patients evaluated, which are common in the carcinogenesis of this cancer. These patients showed a different mutational profile compared to other populations. Our findings confirm the molecular heterogeneity described in the development of colorectal cancer.

Distinct power of bone marrow microRNA signatures and tumor suppressor genes for early detection of acute leukemia.

BACKGROUND: Acute leukemia involving lymphocytic and myeloid cells is cancer with a high mortality rate. Swift and timely diagnosis might be a potential approach to improving patient prognosis and survival. The microRNA (miRNA) signatures are emerging nowadays for their promising diagnostic potential. MiRNA levels from bone marrow can be used as prognostic biomarkers. METHODS: The current study was designed to evaluate if the microRNAs and tumor suppressor genes (TSGs) profiling of hematopoietic bone marrow could help in acute leukemia early detection. Also, we assessed the DNA methyltransferase 3A (DNMT3A) expression and its possible epigenetic effects on miRNAs plus TSGs expression levels. The expression levels of ten miRNAs and four TSGs involved in acute lymphocytic leukemia (ALL) as well as acute myeloid leukemia (AML) were quantified in 43 and 40 bone marrow samples of ALL and AML patients in comparison with cancer-free subjects via real-time quantitative PCR (RT-qPCR). The receiver-operating-characteristic (ROC) analysis of miRNAs was performed in the study groups. Further, the correlation between the DNMT3A and TSGs was calculated. RESULTS: Significant differences were detected in the bone marrow expression of miRNAs and TSGs (P < 0.05) between acute leukemia patients and healthy group. ROC analysis confirmed the ability of miR-30a, miR-101, miR-132, miR-129, miR-124, and miR-143 to discriminate both ALL and AML patients with an area under the ROC curve of ≥ 0.80 (P < 0.001) and high accuracy. The correlation between DNMT3A and P15/P16 TSGs revealed that DNMT3A plays a vital role in epigenetic control of TSGs expression. Our findings indicated that the downregulation of bone marrow miRNAs and TSGs was accompanied by acute leukemia development. CONCLUSIONS: The authors conclude that this study could contribute to introducing useful biomarkers for acute leukemia diagnosis.

The role of EphA7 in different tumors.

Ephrin receptor A7 (EphA7) is a member of the Eph receptor family. It is widely involved in signal transduction between cells, regulates cell proliferation and differentiation, and participates in developing neural tubes and brain. In addition, EphA7 also has a dual role of tumor promoter and tumor suppressor. It can participate in cell proliferation, migration and apoptosis through various mechanisms, and affect tumor differentiation, staging and prognosis. EphA7 may be a potential diagnostic marker and tumor treatment target. This article reviews the effects of EphA7 on a variety of tumor biological processes and pathological characteristics, as well as specific effects and regulatory mechanisms.

Retinoblastoma: from discovery to clinical management.

The retinoblastoma gene (RB1) was the first tumour suppressor cloned; the role of its protein product (RB) as the principal driver of the G1 checkpoint in cell cycle control has been extensively studied. However, many other RB functions are continuously reported. Its role in senescence, DNA repair and apoptosis, among others, is indications of the significance of RB in a vast network of cellular interactions, explaining why RB loss or its malfunction is one of the leading causes of a large number of paediatric and adult cancers. RB was first reported in retinoblastoma, a common intraocular malignancy in the paediatric population worldwide. Currently, its diagnosis is clinical, and in nondeveloped countries, where the incidence is higher, it is performed in advanced stages of the disease, compromising the integrity of the eye and the patient's life. Even though new treatments are being continuously developed, enucleation is still a major choice due to the late disease stage diagnosis and treatments costs. Research into biomarkers is our best option to improve the chances of good results in the treatment and hopes of patients' good quality of life. Here, we recapitulated the history of the disease and the first treatments to put the advances in its clinical management into perspective. We also review the different functions of the protein and the progress in the search for biomarkers. It is clear that there is still a long way to go, but we should offer these children and their families a better way to deal with the disease with the community's effort.

Could dysregulation of RASSF1 expression be a mechanism of tumorigenesis in CTVT? / A desregulação da expressão de RASSF1 pode ser um mecanismo da tumorigênese em TVTC?

Canine transmissible venereal tumor (CTVT) is the oldest known somatic cell lineage. It is a transmissible cancer that propagates naturally in dogs and reportedly contains gene mutations. RASSF1 participates in DNA damage repair, and its downregulation, results in tumor progression. Hence, RASSF1 is a tumor suppressor gene. Its expression was quantified in tumors from seventeen animals and three cell cultures derived from tumors. In general, RASSF1 was underexpressed in 65%, and absent in 35% of tumor samples. Cells from tumor tissue cultures showed decreased expression of RASSF1 in 67% and elevated expression in 33% of samples tested. The tumor tissues showed significantly lower levels of RASSF1 expression compared to cultured cells. Previously we reported that both the tumor microenvironment and the host immune system appear to influence the tumorigenesis and stage of CTVT. This is the first article to demonstrate the expression of RASSF1 in CTVT. Decreased RASSF1 possibly helps tumor progression.

O tumor venéreo transmissível canino (TVTC) é a linhagem de células somáticas mais antiga conhecida. É um câncer transmissível que se propaga naturalmente em cães e mutações genéticas já foram relatadas. O gene RASSF1 atua no reparo de danos ao DNA e presume-se que, quando suprimido ou com expressão gênica reduzida, o TVTC tende a progredir. A expressão do gene supressor de tumor, como RASSF1, foi quantificada em tecidos de dezessete animais e três culturas de células de tecidos tumorais. Em geral, o gene RASSF1 apresentou prevalência de subexpressão (65%) e ausência em 35% dos demais tecidos analisados. Células isoladas de culturas de tecidos tumorais também demonstraram 67% com expressão diminuída e 33% com expressão elevada, com diferença significativa entre os níveis de expressão gênica em amostras de tecido quando comparadas às culturas de células, com tecidos apresentando níveis mais baixos de expressão gênica em comparação com células. Anteriormente, relatamos que tanto o microambiente tumoral quanto o sistema imunológico do hospedeiro parecem influenciar a tumorigênese e o estágio do TVTC. Este é o primeiro artigo a demonstrar a expressão de RASSF1 no TVTC, possivelmente alterando sua tumorigênese e auxiliando no aumento da progressão tumoral.

Somatic Mutational Profile of High-Grade Serous Ovarian Carcinoma and Triple-Negative Breast Carcinoma in Young and Elderly Patients: Similarities and Divergences.

BACKGROUND: Triple-negative breast cancer (TNBC) and High-Grade Serous Ovarian Cancer (HGSOC) are aggressive malignancies that share similarities; however, different ages of onset may reflect distinct tumor behaviors. Thus, our aim was to compare somatic mutations in potential driver genes in 109 TNBC and 81 HGSOC from young (Y ≤ 40 years) and elderly (E ≥ 75 years) patients. METHODS: Open access mutational data (WGS or WES) were collected for TNBC and HGSOC patients. Potential driver genes were those that were present in the Cancer Gene Census-CGC, the Candidate Cancer Gene Database-CCGD, or OncoKB and those that were considered pathogenic in variant effect prediction tools. RESULTS: Mutational signature 3 (homologous repair defects) was the only gene that was represented in all four subgroups. The median number of mutated CGCs per sample was similar in HGSOC (Y:3 vs. E:4), but it was higher in elderly TNBC than it was in young TNBC (Y:3 vs. E:6). At least 90% of the samples from TNBC and HGSOC from Y and E patients presented at least one known affected TSG. Besides TP53, which was mutated in 67-83% of the samples, the affected TSG in TP53 wild-type samples were NF1 (yHGSOC and yTNBC), PHF6 (eHGSOC and yTNBC), PTEN, PIK3R1 and ZHFX3 (yTNBC), KMT2C, ARID1B, TBX3, and ATM (eTNBC). A few samples only presented one affected oncogene (but no TSG): KRAS and TSHR in eHGSOC and RAC1 and PREX2 (a regulator of RAC1) in yTNBC. At least ⅔ of the tumors presented mutated oncogenes associated with tumor suppressor genes; the Ras and/or PIK3CA signaling pathways were altered in 15% HGSOC and 20-35% TNBC (Y vs. E); DNA repair genes were mutated in 19-33% of the HGSOC tumors but were more frequently mutated in E-TNBC (56%). However, in HGSOC, 9.5% and 3.3% of the young and elderly patients, respectively, did not present any tumors with an affected CGC nor did 4.65% and none of the young and elderly TNBC patients. CONCLUSION: Most HGSOC and TNBC from young and elderly patients present an affected TSG, mainly TP53, as well as mutational signature 3; however, a few tumors only present an affected oncogene or no affected cancer-causing genes.

Imunoexpressão da proteína ING3 em Queilites Actínicas e carcinomas de células escamosas de lábio inferior / Immunoexpression of ING3 protein in actinic cheilitis and squamous cell carcinomas of the lower lip

A família de inibidores de crescimento (inhibitor of growth - ING) corresponde a um grupo de genes supressores tumorais cuja expressão se apresenta alterada ou ausente em diversos tipos de câncer. Os produtos destes genes estão relacionados, principalmente, a processos celulares indispensáveis na carcinogênese, como remodelação da cromatina, proliferação celular, replicação e reparo do DNA. Este estudo avaliou a expressão imuno-histoquímica da proteína ING3 em 45 espécimes de queilite actínica (QA) e 48 espécimes de carcinoma de células escamosas de lábio inferior (CCELI). A expressão da proteína foi comparada entre os dois grupos de amostras, bem como com os parâmetros clínico-patológicos das lesões estudadas, através dos testes estatísticos Exato de Fisher, Kruskal-Wallis (KW), Mann-Whitney (U) e teste de correlação de Spearman. Um nível de significância de 5% foi adotado para todos os testes, sendo considerados significativos os valores de p ≤ 0,05. Não foram encontradas associações estatisticamente significativas entre as variáveis morfológicas de CCELI e tamanho do tumor, envolvimento linfonodal, estadiamento clínico, recorrência local e metástase linfonodal após tratamento (p>0,05). Óbitos foram significativamente mais frequentes em tumores de alto escore de risco histopatológico (p<0,05). Nas QAs, diferenças significativas na expressão de ING3 núcleo-citoplasmática, e restrita ao citoplasma, com a gradação de Kujan et al. (2006) foram encontradas (p<0,05). Nos CCELIs, não houve diferença estatisticamente significativa ao comparar as expressões de ING3 (núcleo-citoplasmática e restrita ao citoplasma) com os parâmetros clínicos e morfológicos (p>0,05). A expressão de ING3 núcleo-citoplasmática foi significativamente menor em CCELI quando comparada aos casos de QA (p<0,05) e a expressão restrita ao citoplasma foi significativamente maior nos CCELIs (p<0,05). Nossos resultados sugerem que há notável diminuição da expressão nuclear de ING3 conforme a progressão maligna, indicando função supressora tumoral prejudicada desta proteína em QAs e CCELIs. Entretanto, acredita-se que, na carcinogênese labial, ING3 caracteriza-se melhor como um marcador preditor de transformação maligna, do que um biomarcador de comportamento biológico tumoral (AU).

The family of inhibitors of growth (ING) corresponds to a group of tumor suppressor genes whose expression is altered or absent in several types of cancer. The products of these genes are mainly related to cellular processes indispensable in carcinogenesis, including cell proliferation, DNA replication and repair. This study evaluated the immunohistochemical expression of ING3 protein in 45 actinic cheilitis (AC) and 48 lower lip squamous cell carcinoma (CCELI) specimens. Protein expression was compared between the two groups of samples, as well as with the clinicopathological parameters of studied lesions, using Fisher's exact tests, Kruskal-Wallis (KW), Mann-Whitney (U) and correlation test of Spearman. A significance level of 5% was adopted for all tests, with values of p ≤ 0.05 being considered significant. No statistically significant associations were found between morphological variables of CCELI and tumor size, lymph node involvement, clinical staging, local recurrence and lymph node metastasis after treatment (p>0.05). Deaths were significantly more frequent in tumors with a high histopathological risk score (p<0.05). In ACs, significant differences in nuclear-cytoplasmic and restricted to the cytoplasm expression of ING3, with gradation of Kujan et al. (2006) were found (p<0.05). In CCELIs, there was no statistically significant difference when comparing ING3 expressions (nucleocytoplasmic and cytoplasmic restricted) with clinical and morphological parameters (p>0.05). Nucleocytoplasmic ING3 expression was significantly lower in CCELI when compared to AC cases (p<0.05) and cytoplasm-restricted expression was significantly higher in CCELIs (p<0.05). Our results suggest that there is a remarkable decrease in ING3 nuclear expression according to malignant progression, indicating an impaired tumor suppressor function of this protein in AC and CCELI. However, it is believed that, in lip carcinogenesis, ING3 is better characterized as predictive marker of malignant transformation, rather than a biomarker of tumor biological behavior (AU).

Dysregulation of lncRNA-H19 in cardiometabolic diseases and the molecular mechanism involved : a systematic review.

Introduction: Cardiometabolic diseases are a global public health problem, with significant increases in their prevalence. Different epigenetic factors involved in the progression of metabolic alterations have been described, such as long non-coding RNAs (lncRNAs). H19 is a multifunctional lncRNA expressed from the maternal allele, with low expression after birth, except in the skeletal muscle and heart. Recent studies have linked its dysregulation to alterations in cell metabolism.Areas covered: H19 plays a role in the pathogenesis of coronary artery disease, nonalcoholic fatty liver disease, hepatic and renal fibrosis, insulin resistance, type 2 diabetes, and inflammation. H19 acts mainly as a competitive endogenous RNA of molecules involved in pathways that regulate cell metabolism. In this review, we analyzed the dysregulation of H19 in cardiometabolic diseases and its relationship with molecular alterations in different signaling pathways.Expert opinion: The association of H19 with the development of cardiometabolic diseases, indicates that H19 could be a therapeutic target and prognostic biomarker for these diseases. Controversies have been reported regarding the expression of H19 in some metabolic diseases, therefore, it is necessary to continue research to clarify its pathogenic effect in different organs.

Genes involucrados en el cáncer pulmonar / Genes involved in lung cancer

Introducción: El cáncer pulmonar constituye un serio problema de salud mundial por su elevada prevalencia y mortalidad. En la carcinogénesis pulmonar están implicados oncogenes y genes supresores tumorales, que en una compleja interacción con factores ambientales favorecen la transformación cancerosa. Objetivo: Describir los principales genes implicados en el cáncer pulmonar. Métodos: Se buscaron referencias en las bases de datos PubMed Central, Annual Reviews y SciELO. Se revisaron preferentemente los artículos originales, las revisiones bibliográficas, las revisiones sistemáticas y los metaanálisis de los últimos cinco años. Análisis e integración de la información: En la carcinogénesis pulmonar se involucran los oncogenes JUN, FOS, ABL1, BRAF, RAF1, GNAS, KRAS, NRAS, HRAS, CSF 1R, MYC, EGFR, MET, ALK, CCNE1, DDR2, ERBB3, FGFR1, MDM2, ROS1, SOX2 y TP63 y los genes supresores tumorales TP53, CDKN2A, CDKN1A, RB1, CDK2AP1, ATM, ERCC2, BRCA1, CCND1, STK11, PDLIM2, PTEN, ARID1A, ASCL4, CUL3, EP300, KEAP1, KMT2D, NF1, NOTCH1, RASA1, ETD2 y SMARCA4. El conocimiento de la genética molecular del cáncer pulmonar es importante para la identificación de biomarcadores diagnósticos y pronósticos más eficaces y para el diseño de fármacos diana sobre genes específicos(AU)

Introduction: Lung cancer is a serious global health problem due to its high prevalence and mortality. Lung carcinogenesis involves oncogenes and tumor suppressor genes which interact in complex manners with environmental factors, paving the way for the cancerous transformation. Objective: Describe the main genes involved in lung cancer. Methods: References were searched for in the databases PubMed Central, Annual Reviews and SciELO. Particular attention was paid to original papers, bibliographic reviews, systematic reviews and meta-analyses published in the last five years. Data analysis and integration: Lung carcinogenesis involves the oncogenes JUN, FOS, ABL1, BRAF, RAF1, GNAS, KRAS, NRAS, HRAS, CSF 1R, MYC, EGFR, MET, ALK, CCNE1, DDR2, ERBB3, FGFR1, MDM2, ROS1, SOX2 and TP63, and the tumor suppressor genes TP53, CDKN2A, CDKN1A, RB1, CDK2AP1, ATM, ERCC2, BRCA1, CCND1, STK11, PDLIM2, PTEN, ARID1A, ASCL4, CUL3, EP300, KEAP1, KMT2D, NF1, NOTCH1, RASA1, ETD2 and SMARCA4. Knowledge about the molecular genetics of lung cancer is important to identify more efficient diagnostic and prognostic biomarkers and to design targeted drugs for specific genes(AU)

A novel tumor suppressor CECR2 down regulation links glutamine metabolism contributes tumor growth in laryngeal squamous cell carcinoma.

PURPOSE: Glutamine plays an important role in tumor metabolism and progression. This research aimed to find out how Gln exert their effects on laryngeal squamous cell carcinoma (LSCC). METHODS: Cell proliferation was measured by CCK8 and EdU assay, mitochondrial bioenergetic activity was measured by mitochondrial stress tests. Gene expression profiling was revealed by RNA sequencing and validated by RT-qPCR. In LSCC patients, protein expression in tumor and adjacent tissues was examined and scored by IHC staining. RNAi was performed by stably expressed shRNA in TU177 cells. In vivo tumor growth analysis was performed using a nude mouse tumorigenicity model. RESULTS: Gln deprivation suppressed TU177 cell proliferation, which was restored by αKG supplementation. By transcriptomic analysis, we identified CECR2, which encodes a histone acetyl-lysine reader, as the downstream target gene for Gln and αKG. In LSCC patients, the expression of CECR2 in tumors was lower than adjacent tissues. Furthermore, deficiency of CECR2 promoted tumor cell growth both in vitro and in vivo, suggesting it has tumor suppressor effects. Besides, cell proliferation inhibited by Gln withdrawal could be restored by CECR2 depletion, and the proliferation boosted by αKG supplementation could be magnified either, suggested that CECR2 feedback suppressed Gln and αKG's effect on tumor growth. Transcriptomic profiling revealed CECR2 regulated the expression of a series of genes involved in tumor progression. CONCLUSION: We confirmed the Gln-αKG-CECR2 axis contributes to tumor growth in LSCC. This finding provided a potential therapeutic opportunity for the use of associated metabolites as a potential treatment for LSCC.

Positive selection and gene duplications in tumour suppressor genes reveal clues about how cetaceans resist cancer.

Cetaceans are the longest-living species of mammals and the largest in the history of the planet. They have developed mechanisms against diseases such cancer, although the underlying molecular bases of these remain unknown. The goal of this study was to investigate the role of natural selection in the evolution of 1077 tumour suppressor genes (TSGs) in cetaceans. We used a comparative genomic approach to analyse two sources of molecular variation in the form of dN/dS rates and gene copy number variation. We found a signal of positive selection in the ancestor of cetaceans within the CXCR2 gene, an important regulator of DNA damage, tumour dissemination and immune system. Further, in the ancestor of baleen whales, we found six genes exhibiting positive selection relating to diseases such as breast carcinoma, lung neoplasm (ADAMTS8) and leukaemia (ANXA1). The TSGs turnover rate (gene gain and loss) was almost 2.4-fold higher in cetaceans when compared with other mammals, and notably even faster in baleen whales. The molecular variants in TSGs found in baleen whales, combined with the faster gene turnover rate, could have favoured the evolution of their particular traits of anti-cancer resistance, gigantism and longevity. Additionally, we report 71 genes with duplications, of which 11 genes are linked to longevity (e.g. NOTCH3 and SIK1) and are important regulators of senescence, cell proliferation and metabolism. Overall, these results provide evolutionary evidence that natural selection in TSGs could act on species with large body sizes and extended lifespan, providing novel insights into the genetic basis of disease resistance.

Impact of Reck expression and promoter activity in neuronal in vitro differentiation.

Reck (REversion-inducing Cysteine-rich protein with Kazal motifs) tumor suppressor gene encodes a multifunctional glycoprotein which inhibits the activity of several matrix metalloproteinases (MMPs), and has the ability to modulate the Notch and canonical Wnt pathways. Reck-deficient neuro-progenitor cells undergo precocious differentiation; however, modulation of Reck expression during progression of the neuronal differentiation process is yet to be characterized. In the present study, we demonstrate that Reck expression levels are increased during in vitro neuronal differentiation of PC12 pheochromocytoma cells and P19 murine teratocarcinoma cells and characterize mouse Reck promoter activity during this process. Increased Reck promoter activity was found upon induction of differentiation in PC12 cells, in accordance with its increased mRNA expression levels in mouse in vitro models. Interestingly, Reck overexpression, prior to the beginning of the differentiation protocol, led to diminished efficiency of the neuronal differentiation process. Taken together, our findings suggest that increased Reck expression at early stages of differentiation diminishes the number of neuron-like cells, which are positive for the beta-3 tubulin marker. Our data highlight the importance of Reck expression evaluation to optimize in vitro neuronal differentiation protocols.

PALB2 Variants: Protein Domains and Cancer Susceptibility.

Since its discovery, partner and localizer of breast cancer 2 (BRCA2) (PALB2) has emerged as a major tumor suppressor gene linked to breast cancer (BC), pancreatic cancer (PC), and ovarian cancer (OC) susceptibility. Its protein product plays a pivotal role in the maintenance of genome integrity. Here we discuss the first functional evaluation of a large set of PALB2 missense variants of uncertain significance (VUSs). Assessment of 136 VUSs interrogating a range of PALB2 biological functions resulted in the identification of 15 variants with consistent loss of function across different assays. All loss-of-function variants are located at the PALB2 coiled coil (CC) or at the WD40 domain, highlighting the importance of modular domains mechanistically involved in the DNA damage response (DDR) and pinpointing their roles in tumor suppression.

Vías moleculares patogénicas del linfoma T/NK extranodal de tipo nasal asociadas con virus de Epstein Barr: Revisión narrativa / Molecular pathways related to Epstein Barr virus in extranodal NK/T cell lymphoma, nasal type: Narrative review

El virus de Epstein Barr (VEB) se encuentra presente en el 100% de los casos de linfoma T/NK extranodal de tipo nasal (ENKTL) y juega un papel importante en la etiopatogenia de esta enfermedad. El objetivo de esta revisión es actualizar el conocimiento de las vías moleculares genéticas y epigenéticas utilizadas por el VEB en la oncogenesis del ENKTL. Para ello se realizó una revisión de la literatura, en las bases de datos de PubMed y Google Scholar, sobre los mecanismos que utilizan las proteínas virales como la proteína de membrana latente (LMP1) y el antígeno nuclear Epstein Barr 1 (EBNA1) para activar proteínas antiapoptóticas del huésped y pro-teínas relacionadas a proliferación celular, a través de las vías moleculares JAK/STAT (Janus quinasas/señales de transducción y activación de proteínas de transcripción), NF-κB (el factor nuclear potenciador de las cadenas ligeras kappa de las células B activadas) EZHZ2 (Enhancer of Zeste 2 Polycomb repressive Complex 2) y PI3K/Akt (Fosfoinositido 3 quinasa/proteína quinasa B); también se revisó el papel de las proteínas virales BNLF2a, BILF y BDLF3 en la evasión inmune del virus. También LMP1 aumenta la expresión de PDL-1 (ligando de la muerte celular programada), contribuyendo a la disminución de la respuesta inmunológica. A nivel epigenético se abordan los cambios del perfil de metilación en las áreas promotoras de genes supresores de tumor y se explica la función de los miARN de VEB que participan inhibiendo genes supresores de tumor o activando genes que aumentan la proliferación.

Epstein Barr virus (EBV) is present in 100% of cases of nasal-type extranodal NK/T cell lymphoma (ENKTL). It plays an important role in the etiopathogenesis of this disease. The objective of this review is to update the knowledge of the genetic and epigenetic molecular pathways used by EBV in the oncogenesis of ENKTL. To this end, a literature review was carried out in the PubMed and Google Scholar databases on the mechanisms used by viral proteins such as latent membrane protein (LMP1) and Epstein Barr 1 nuclear antigen (EBNA1) to activate host antiapoptotic proteins avoiding cell death and activating cell proliferation, through the molecular pathways JAK/STAT (Janus kinases/signal transduction and activation of transcription proteins), NF-κB (the nuclear factor enhancing the kappa light chains of activated B cells) EZHZ2 pathways (Enhancer of Zeste 2 Polycomb repressive Complex 2) and PI3K/Akt (Phosphoinositide 3 kinase protein kinase B). The role of the viral proteins: BNLF2a, BILF and BDLF3 in the virus immune evasion. It is currently recognized that LMP1 increases the expression of PDL-1 (programmed cell death ligand), contributing to the decrease in the immune response. Thus, the epigenetic changes in the methylation profile in the promoter areas of tumor suppressor genes, was also reviewed. Finally role of EBV miRNAs participate in inhibiting tumor suppressor genes or activating genes that increase proliferation.