Genes and Cancer最新文献

Retinoblastoma (Rb1) is a gene that codes for a tumour suppressor protein involved in various types of cancer. It was first described in retinoblastoma and is segregated as an autosomal dominant trait with high penetrance. In 1971, Knudson proposed his hypothesis of the two hits, where two mutational events are required to initiate tumour progression. We analysed three different point mutations present in patients' retinoblastoma. We produced three cell lines with retinoblastoma protein (RB) mutated in various regions: the missense pN328H, pD718N, and the nonsense early stop codon pR552*. We studied the effect of these point mutations on levels of mRNA and protein expression, proliferation, viability, localisation, and migration using an RBKO cell line. All three affected their localisation patterns and proliferation. However, the pR552* mutation also increases viability and migration. Moreover, when this mutation is simultaneously expressed with a wild-type RB, the phenotype and proliferation parameters are as with the mutant alone, suggesting that maybe only one mutated allele is needed to trigger the characteristic cancer phenotype. In other words, the pR552* mutant behaves more like a gain-of-function or oncogenic mutant. Indeed, a family carrying this mutation showed complete penetrance and high expressivity.

Background: In some breast cancers, altered estrogen-sulfotransferase (SULT1E1) and its inactivation by oxidative-stress modifies E2 levels. Parallelly, hypoxia-inducible tissue-damaging factors (HIF1α) are induced. The proteins/genes expressions of these factors were verified in human-breast-cancer tissues. SULT1E1 inducing-drugs combinations were tested for their possible protective effects.

Methods: Matrix-metalloproteases (MMP2/9) activity and SULT1E1-HIF1α protein/gene expression (Western-blot/RTPCR) were assessed in breast-cancers versus adjacent-tissues. Oxidant-stress neutralizer, chalcone (trans-1,3-diaryl-2-propen-1-ones) and SULT1E1-inducer pure dialyl-sulfide (garlic; Allium sativum) were tested to prevent cancer causing factors in rat, in-vitro and in-vivo. The antioxidant-enzymes SOD1/catalase/GPx/LDH and matrix-degenerating MMP2/9 activities were assessed (gel-zymogram). Histoarchitecture (HE-staining) and tissue SULT1E1-localization (immuno-histochemistry) were screened. Extensive statistical-analysis were performed.

Results: Human cancer-tissue expresses higher SULT1E1, HIF1α protein/mRNA and lower LDH activity. Increase of MMP2/9 activities commenced tissue damage. However, chalcone and DAS significantly induced SULT1E1 gene/protein, suppressed HIF1α expression, MMP2/9 activities in rat tissues. Correlation and group statistics of t-test suggest significant link of oxidative-stress (MDA) with SULT1E1 (p = 0.006), HIF1α (p = 0.006) protein-expression. The non-protein-thiols showed negative correlation (p = 0.001) with HIF1α. These proteins and SULT1E1-mRNA expressions were significantly higher in tumor (p < 0.05). Correlation data suggest, SULT1E1 is correlated with non-protein-thiols.

Conclusions: Breast cancers associate with SULT1E1, HIF1α and MMPs deregulations. For the first time, we are revealing that advanced cancer tissue with elevated SULT1E1-protein may reactivate in a reducing-state initiated by chalcone, but remain dormant in an oxidative environment. Furthermore, increased SULT1E1 protein synthesis is caused by DAS-induced mRNA expression. The combined effects of the drugs might decrease MMPs and HIF1α expressions. Further studies are necessary.

The MYC gene is a regulatory and proto-oncogenic gene that is overexpressed in the majority of prostate cancers (PCa). Numerous studies have indicated that aberrant expression of microRNAs is involved in the initiation and progression of prostate cancer. In this investigation, we assessed the impact of miR-377 on MYC through luciferase assay. Real-time PCR was employed to determine whether miR-377 could reduce the levels of MYC mRNA in transfected PCa cell lines (PC-3 and DU145) and change in the mRNA levels of BCL-2/Bax, PTEN, and CDK4 as a consequence of MYC downregulation. Moreover, we analyzed the effects of miR-377 on apoptosis, proliferation, cell cycle, and wound healing. Our findings demonstrate that miR-377 effectively targets MYC mRNA, as confirmed by luciferase assay and Real-time PCR. We observed a significant reduction in BCL-2 and CDK4 expression, along with an increase in Bax and PTEN, in prostate cancer cell lines upon MYC suppression. Additionally, elevated levels of miR-377 in PCa cell lines induced apoptosis, inhibited proliferation and migration, and arrested the cell cycle. Taken together, these results unveil the inhibitory role of miR-377 in MYC function within PCa, thereby suggesting its potential as a therapeutic target for the treatment of this malignancy.

Ewing sarcoma is a cancer of bone and soft tissue in children and young adults that is driven by the EWS-ETS fusion transcription factor, most commonly EWS-FLI1. We previously reported that Ewing sarcoma harbors two populations of cells, the CD133^high population displaying higher growth rate and the CD133^low population displaying chemotherapy resistance. We now find that the ubiquitin-specific protease 1 (USP1) is a transcriptional target of the EWS-FLI1 fusion oncoprotein, expressed at high and low levels in the CD133^high and the CD133^low populations, respectively, and determines chemo-sensitivity. We also find that USP1 inhibits cdc42, increases EWS-FLI1 transcriptional output, and simulates Ewing sarcoma growth. We show that chemo-sensitization by USP1 is independent of cdc42. A pharmacological inhibitor of USP1 was able to activate cdc42 and inhibit Ewing sarcoma growth. These results uncover critical roles for USP1 in Ewing sarcoma, which regulates growth and chemo-sensitivity via distinct mechanisms.

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer worldwide but is often diagnosed at an advanced incurable stage. Yet, despite the urgent need for blood-based biomarkers for early detection, few studies capture ongoing biology to identify risk-stratifying biomarkers. We address this gap using the TGF-β pathway because of its biological role in liver disease and cancer, established through rigorous animal models and human studies. Using machine learning methods with blood levels of 108 proteomic markers in the TGF-β family, we found a pattern that differentiates HCC from non-HCC in a cohort of 216 patients with cirrhosis, which we refer to as TGF-β based Protein Markers for Early Detection of HCC (TPEARLE) comprising 31 markers. Notably, 20 of the patients with cirrhosis alone presented an HCC-like pattern, suggesting that they may be a group with as yet undetected HCC or at high risk for developing HCC. In addition, we found two other biologically relevant markers, Myostatin and Pyruvate Kinase M2 (PKM2), which were significantly associated with HCC. We tested these for risk stratification of HCC in multivariable models adjusted for demographic and clinical variables, as well as batch and site. These markers reflect ongoing biology in the liver. They potentially indicate the presence of HCC early in its evolution and before it is manifest as a detectable lesion, thereby providing a set of markers that may be able to stratify risk for HCC.

Background: In the pediatric patient, central venous catheterization may be associated with relevant complications. Though, most of them may be prevented by a wise choice of materials, methods, and techniques. Evidence-based insertion bundles for central venous catheterization have been developed in the adult patient, but not in neonates and children.

Methods: The Italian Group for Long Term Venous Access Devices (GAVeCeLT) has developed an insertion bundle for central venous catheterization in neonates, infants, and children, which includes seven evidence-based strategies: (1) preprocedural ultrasound evaluation, (2) appropriate aseptic technique, (3) ultrasound guided venipuncture, (4) intraprocedural tip location by non-radiological methods, (5) proper choice of the exit site by tunneling, (6) sutureless securement, and (7) protection of the exit site using glue and transparent membranes. The effectiveness and safety of this bundle has been tested in a prospective study.

Results: All neonates, infants and children requiring a non-emergency central line (except for umbilical venous catheters and epicutaneo-cava catheters) were included in the study. Out of 729 central line insertions, there were no immediate complications (no pneumothorax, no arterial puncture, no malposition); the incidence of early and late complications (local ecchymosis, dislodgment, local pain, exit site infection) was 3.7%; in the first 2 weeks after insertion, no catheter-related bacterial infection or catheter-related thrombosis was recorded.

Conclusion: The results of this prospective study strongly validate the hypothesis that an insertion bundle is highly effective in optimizing the safety of the maneuver, reducing immediate, early, and late complications.

Chemoresistance in ovarian carcinoma is a puzzling issue that urges understanding of strategies used by cancer cells to survive DNA damage and to escape cell death. Expanding efforts to understand mechanisms driving chemoresistance and to develop alternative therapies targeting chemoresistant tumors are critical. Amplification of BRD4 is frequently associated with chemoresistant ovarian carcinoma, but little is known about the biological effects of the overexpression of BRD4 isoforms in this malignancy. Here, we described the consequences of BRD4-L and BRD4-S overexpression in ovarian carcinoma shedding a light on a complex regulation of BRD4 isoforms. We demonstrated that the BRD4-L transcript expression is required to generate both isoforms, BRD4-L and BRD4-S. We showed that the BRD4-S mRNA expression positively correlated with BRD4-S protein levels, while BRD4-L isoform showed negative correlation between mRNA and protein levels. Moreover, we demonstrated that an overexpression of BRD4 isoforms is associated with chemoresistance in ovarian cancer.

We and others have recently shown that proteins involved in the DNA damage response (DDR) are critical for KRAS-mutant pancreatic ductal adenocarcinoma (PDAC) cell growth in vitro. However, the CRISPR-Cas9 library that enabled us to identify these key proteins had limited representation of DDR-related genes. To further investigate the DDR in this context, we performed a comprehensive, DDR-focused CRISPR-Cas9 loss-of-function screen. This screen identified valosin-containing protein (VCP) as an essential gene in KRAS-mutant PDAC cell lines. We observed that genetic and pharmacologic inhibition of VCP limited cell growth and induced apoptotic death. Addressing the basis for VCP-dependent growth, we first evaluated the contribution of VCP to the DDR and found that loss of VCP resulted in accumulation of DNA double-strand breaks. We next addressed its role in proteostasis and found that loss of VCP caused accumulation of polyubiquitinated proteins. We also found that loss of VCP increased autophagy. Therefore, we reasoned that inhibiting both VCP and autophagy could be an effective combination. Accordingly, we found that VCP inhibition synergized with the autophagy inhibitor chloroquine. We conclude that concurrent targeting of autophagy can enhance the efficacy of VCP inhibitors in KRAS-mutant PDAC.

In recent years, immunotherapy has finally found its place in the anti-cancer therapeutic arsenal, even becoming standard of care as first line treatment for metastatic forms. The clinical benefit provided by checkpoint blockers such as anti-PD-1/PD-L1 in many cancers revolutionized the field. However, too many patients remain refractory to these treatments due to weak baseline anti-cancer immunity. There is therefore a need to boost the frequency and function of patients' cytotoxic CD8+ cellular effectors by targeting immunogenic and tumor-restricted antigens, such as neoantigens using an efficient vaccination platform. Dendritic cells (DC) are the most powerful immune cell subset for triggering cellular immune response. However, autologous DC-based vaccines display several limitations, such as the lack of reproducibility and the limited number of cells that can be manufactured. Here we discuss the advantages of a new therapeutic vaccine based on an allogeneic Plasmacytoid DC cell line, which is easy to produce and represents a powerful platform for priming and expanding anti-neoantigen cytotoxic CD8+ T-cells.