Unraveling the Interplay of KRAS, NRAS, BRAF, and Micro-Satellite Instability in Non-Metastatic Colon Cancer: A Systematic Review.

Microsatellite Instability (MSI-H) occurs in approximately 15% of non-metastatic colon cancers, influencing patient outcomes positively compared to microsatellite stable (MSS) cancers. This systematic review focuses on the prognostic significance of KRAS, NRAS, and BRAF mutations within MSI-H colon cancer. Through comprehensive searches in databases like MEDLINE, EMBASE, and others until 1 January 2024, we selected 8 pertinent studies from an initial pool of 1918. These studies, encompassing nine trials and five observational studies involving 13,273 patients, provided insights into disease-free survival (DFS), survival after recurrence, and overall survival. The pooled data suggest that while KRAS and BRAF mutations typically predict poorer outcomes in MSS colorectal cancer, their impact is less pronounced in MSI contexts, with implications varying across different stages of cancer and treatment responses. In particular, adverse effects of these mutations manifest significantly upon recurrence rather than affecting immediate DFS. Our findings confirm the complex interplay between genetic mutations and MSI status, emphasizing the nuanced role of MSI in modifying the prognostic implications of KRAS, NRAS, and BRAF mutations in colon cancer. This review underscores the importance of considering MSI alongside mutational status in the clinical decision-making process, aiming to tailor therapeutic strategies more effectively for colon cancer patients.

Use of DNA-alkylating pyrrole-imidazole polyamides for anti-cancer drug sensitivity screening in pancreatic ductal adenocarcinoma.

BACKGROUND: Activating mutations of the KRAS occurs in >90% of pancreatic ductal adenocarcinoma (PDAC) cases. However, direct pharmacological targeting of the activated KRAS protein has been challenging. We previously reported that KR12, a DNA-alkylating pyrrole-imidazole polyamide designed to recognize the KRAS G12D/V mutation, showed an anti-tumor effect in colorectal cancer. In this study, we evaluated the anti-tumor effect of KR12 in PDAC. METHODS: KR12 was synthesized by an automated peptide synthesizer PSSM-8 and tested for anti-tumor effect in PDAC mouse models. RESULT: KR12 inhibited tumor growth in a spontaneous PDAC mouse model, although the anti-tumor activity appeared to be limited in a human PDAC xenograft model. We developed a pyrrole-imidazole polyamide screening process based on the hypothesis that genetic elements otherwise unaffected by KR12 could exert attenuating effects on KRAS-suppression-resistant PDAC. We identified RAD51 as a potential therapeutic target in human PDAC cells. A RAD51 inhibitor showed an inhibitory effect on cell growth and affected the cytotoxic activity of KR12 in PDAC cells. CONCLUSION: These data suggested that the simultaneous inhibition of RAD51 and mutant KRAS blockage would be an important therapeutic strategy for PDAC.

KRAS G12D Mutation Subtype in Pancreatic Ductal Adenocarcinoma: Does It Influence Prognosis or Stage of Disease at Presentation?

Background: KRAS G12D mutation subtype is present in over 40% of pancreatic ductal adenocarcinoma (PDAC), one of the leading global causes of cancer death. This retrospective cohort study aims to investigate whether detection of the KRAS G12D mutation subtype in PDAC patients is a determinant of prognosis across all stages of disease. Methods: We reviewed the medical records of 231 patients presenting with PDAC at a large tertiary hospital, and compared survival using the Kaplan Meier, log-rank test and Cox proportional hazards regression model. Results: KRAS G12D mutation subtype was not significantly associated with poorer survival compared across the whole population of PDAC patients (p = 0.107; HR 1.293 95% CI (0.946-1.767)). However, KRAS G12D patients who were resectable had a shorter median survival time of 356 days compared to all other genotypes (median survival 810 days) (p = 0.019; HR 1.991 95% CI (1.121-3.537)). Conclusions: KRAS G12D patients who were resectable at diagnosis had shorter survival compared to all other PDAC patients. These data suggest that KRAS G12D may be a clinically useful prognostic biomarker of PDAC.

Correlation of miR-31 and miR-373 expression with KRAS mutations and its impact on prognosis in colorectal cancer.

INTRODUCTION: Colorectal cancers (CRC) are among the most common cancers. There are different modalities for treatment including chemotherapy, surgery, and radiotherapy. There are some mutations in cancers which can assist in the treatment and better prognosis of patients. In this study, two molecular markers (miR-31 and miR-373) were involved in the pathogenesis of CRC and their association with histopathological features was investigated. As well, the prognostic value of these molecular markers was investigated in CRC patients with or without common KRAS mutations. METHODS: Paraffin blocks of tissue samples from 150 patients who underwent colon surgery between 2018 and 2020 were prepared by the Pathology Department of Imam Hossein Hospital (Tehran, Iran). After DNA and RNA isolation, gene expression of miR-31 and miR-373 was determined using probe-based quantitative real-time polymerase chain reaction (qRT-PCR). Mutations of KRAS were surveyed using conventional PCR and agarose gel electrophoresis. RESULTS: The mean age of the patients was 57.2 ± 13.4 years. KRAS codon 12 and 13 mutations were positive in 31 (20.6%) and 22 (14.6%) cases, respectively. The results showed that KRAS common mutations occurred in 32.6% of Iranian CRC patients. The expression levels of miR-31 and miR-373 increased in CRC patients with KRAS mutations in comparison with patients without these mutations. CONCLUSION: Considering the role of miR-31 and miR-373 in CRC tumor progression, it seems that the CRC patients bearing KRAS mutations have a poorer prognosis respective to patients without KRAS mutations.

Somatic mutation analysis of Mesonephric-Like adenocarcinoma and associated putative precursor Lesions: Insight into pathogenesis and potential molecular treatment targets.

Aims: Mesonephric-like adenocarcinoma (MLA) is a recently described histologic tumor subtype of the Müllerian tract. MLA can arise in association with Müllerian lesions that share common mutations. We report three MLAs and hypothesize that concurrent endometriosis and cystadenofibroma with focal borderline changes might also carry common mutations. Methods and results: We searched "mesonephric" in our database from 2015 to mid-2021 to retrieve MLA cases. Somatic mutation analysis was performed on tumors and on associated benign proliferative lesions. All MLAs (2 ovarian and 1 uterine) harbored KRAS G12D or G12 V mutations. A PIK3CA alteration (H1047Q) was detected in one MLA and in the associated cystadenofibroma with focal borderline changes. The molecular profile of MLA-associated Müllerian lesions (endometriosis and seromucinous cystadenofibroma with focal borderline changes) was similar to concurrent adenocarcinoma. However, tumor contamination could not be excluded in the endometriotic lesion. Patients presented at various stages, with no evidence of post-operative recurrence after 15 months (FIGO IC) and 33 months (FIGO IIA2). One patient (FIGO IIIA1) died of disease 32 months after surgery. Conclusions: KRAS mutations commonly characterize MLA. At least some MLA-associated Müllerian lesions show MLA-like genetic profiles, suggesting a precursor role. As far as we are aware, we describe for the first time in MLA the potentially actionable H1047Q variant of PIK3CA.

Mutational status may supersede tumor size in predicting the presence of aggressive pathologic features in well differentiated thyroid cancer.

BACKGROUND: In clinical practice, thyroid tumor size plays a critical role in the staging of thyroid malignancies and in the selection of nodules that should undergo ultrasound-guided fine-needle aspiration. Thyroid tumor size is influenced by the elapsed time since the beginning of oncogenesis and by the presence of somatic mutations driving growth, such as BRAFV600E mutations, associated with aggressive phenotypes, and RAS-like mutations, associated with more indolent behavior. Although large nodules are often considered to be more alarming, the true impact of tumor size on prognosis remains controversial. The aim of this study was to assess the relationship between mutational status, tumor size and aggressiveness, with emphasis on BRAFV600E and RAS-like mutations. METHOD: We conducted a multicentric retrospective chart review in Montréal, Canada, of all patients who underwent thyroid surgery between January 2016 and December 2020, with well-differentiated thyroid cancer on final pathology, and who had undergone molecular testing revealing the presence of BRAFV600E mutations or RAS-like mutations (NRAS, HRAS or KRAS). RESULTS: We included 214 cases. There were 117 (54.7%) cases of BRAFV600E and 97 (45.3%) cases of RAS-like mutations. The BRAFV600E group was statistically associated with a smaller mean tumor size when compared with the RAS group of 1.55 cm and 2.04 cm, respectively. In a multivariate model, tumors with BRAFV600E mutations were also more likely to display aggressive pathological features, including extra-thyroidal extension, lymph node metastasis, columnar cell features, tall cell histology, or hobnail histology (OR 26.69; 95% CI 11.15-70.81). In contrast, tumor size was not associated with pathologic aggressive features on multivariate analysis (OR 0.81; 95% CI 0.54-1.22). CONCLUSION: This study demonstrates that thyroid tumors expressing BRAFV600E mutations correlate with aggressive pathologic features more than tumors expressing RAS-like mutations. When comparing tumors with BRAFV600E and RAS-like mutations, the former were found to be smaller. As a result of this finding, this study suggests that molecular alterations may better predict aggressive pathologic features than the size of the tumor.

Evaluation and diagnostic value of next-generation sequencing analysis of residual liquid-based cytology specimens of pancreatic masses.

BACKGROUND: Liquid-based cytology (LBC) is a widely used method for processing specimens obtained by endoscopic biopsy. This study evaluated next-generation sequencing (NGS) analysis of LBC specimens to improve the diagnostic accuracy of pancreatic lesions. METHODS: Upon the diagnosis of a suspected pancreatic mass, LBC residues were used retrospectively. The quantity and quality of DNA extracted from residual LBC samples were evaluated, and an NGS analysis targeting 6 genes (KRAS, GNAS, TP53, CDKN2A, SMAD4, and PIK3CA) was performed. RESULTS: The library was prepared from LBC specimens taken from 52 cases: 44 were successful, and 8 preparations failed. An analysis of DNA quantity and quality suggested that the success or failure of NGS implementation depended on both properties. The final diagnosis was achieved by a combination of the pathological analysis of the surgical excision or biopsy material with clinical information. Among the 33 cases of pancreatic ductal adenocarcinoma (PDAC), KRAS, TP53, CDKN2A, and SMAD4 mutations were identified in 31 (94%), 16 (48%), 3 (9%), and 2 (6%), respectively. Among the 11 benign cases, only a KRAS mutation was identified in 1 case. On the basis of NGS results, 18 of 33 PDACs (55%) were classified as highly dysplastic or more, and 10 of 11 benign lesions were evaluated as nonmalignant, which was consistent with the final diagnosis. CONCLUSIONS: NGS analysis using LBC specimens from which DNA of appropriate quantity and quality has been extracted could contribute to improving the assessment of pancreatic tumor malignancies and the application of molecular-targeted drugs.

RGD4C peptide mediates anti-p21Ras scFv entry into tumor cells and produces an inhibitory effect on the human colon cancer cell line SW480.

BACKGROUND: We prepared an anti-p21Ras scFv which could specifically bind with mutant and wild-type p21Ras. However, it cannot penetrate the cell membrane, which prevents it from binding to p21Ras in the cytoplasm. Here, the RGD4C peptide was used to mediate the scFv penetration into tumor cells and produce antitumor effects. METHODS: RGD4C-EGFP and RGD4C-p21Ras-scFv recombinant expression plasmids were constructed to express fusion proteins in E. coli, then the fusion proteins were purified with HisPur Ni-NTA. RGD4C-EGFP was used as reporter to test the factors affecting RGD4C penetration into tumor cell. The immunoreactivity of RGD4C-p21Ras-scFv toward p21Ras was identified by ELISA and western blotting. The ability of RGD4C-p21Ras-scFv to penetrate SW480 cells and colocalization with Ras protein was detected by immunocytochemistry and immunofluorescence. The antitumor activity of the RGD4C-p21Ras-scFv was assessed with the MTT, TUNEL, colony formation and cell migration assays. Chloroquine (CQ) was used an endosomal escape enhancing agent to enhance endosomal escape of RGD4C-scFv. RESULTS: RGD4C-p21Ras-scFv fusion protein were successfully expressed and purified. We found that the RGD4C fusion protein could penetrate into tumor cells, but the tumor cell entry of was time and concentration dependent. Endocytosis inhibitors and a low temperature inhibited RGD4C fusion protein endocytosis into cells. The change of the cell membrane potential did not affect penetrability. RGD4C-p21Ras-scFv could penetrate SW480 cells, effectively inhibit the growth, proliferation and migration of SW480 cells and promote this cells apoptosis. In addition, chloroquine (CQ) could increase endosomal escape and improve antitumor activity of RGD4C-scFv in SW480 cells. CONCLUSION: The RGD4C peptide can mediate anti-p21Ras scFv entry into SW480 cells and produce an inhibitory effect, which indicates that RGD4C-p21Ras-scFv may be a potential therapeutic antibody for the treatment of ras-driven cancers.

Inhibition of glioma by adenovirus KGHV500 encoding anti-p21Ras scFv and carried by cytokine-induced killer cells.

Ras gene mutation or overexpression can lead to tumorigenesis in multiple kinds of cancer, including glioma. However, no drugs targeting Ras or its expression products have been approved for clinical application thus far. Adenoviral gene therapy is a promising method for the treatment of glioma. In this study, the human glioma cell line U251 was co-cultured with recombinant adenovirus KGHV500, and the anti-tumor effects of KGHV500 were determined by MTT, scratch test, Transwell invasion, and apoptosis assays. Then, KGHV500 was delivered via the intravenous injection of CIK cells into glioma xenografts. Tumor volume, ki67 proliferation index, apoptosis levels, and anti-p21Ras scFv expression were tested to evaluate targeting ability, anti-tumor efficacy, and safety. We found that the KGHV500 exhibited anti-tumor activity in U251 cells and increased the intracellular expression of anti-p21Ras scFv compared with that in the control groups. CIK cells delivered KGHV500 to U251 glioma cell xenografts and enhanced anti-tumor activity against glioma xenografts compared to that produced by the control treatment. In conclusion, targeting Ras is a useful therapeutic strategy for gliomas and other Ras-driven cancers, and the delivery of anti-p21Ras scFv by recombinant adenovirus and CIK cells may play an essential role in the therapy of Ras-driven cancers.

p53 and p21 expression in bone marrow clots of megaloblastic anemia patients.

The pathogenesis of megaloblastic hemopathies (MH) is centered on the deficiency of vitamin B12 and folic acid with interruption of erythrocyte maturation. This study researched the participation of p53 and p21 in the pathophysiology of the disease. A retrospective study enrolled 95 patients with histopathologic diagnosis by biopsy or bone marrow clot (BMB/BMC), with clinical review and immunohistochemical study in tissue microarray (TMA) for p53 and p21, detailing their marking location. All patients had BMC and only 11 had BMB. The CMO was a differential of this study and it allowed an expanded sample. In the TMA, 63.7% (58/91) of the samples were immunopositive for p53; and 35.2% (31/88) were immunopositive for p21. Nuclear staining, divergent from the literature, was observed in 17.3% (10/58) among those p53+ and in 38.7% (12/31) among those p21+. The pattern of immunostaining showed non-significant differences (P=0.474) regarding morphologic and clinical aspects. The positivity for both may indicate an effective balance between apoptosis and anti-apoptotic action. Excessive inhibition of apoptosis would contribute to high global cellularity, but without functional maturation effectiveness. In conclusion, there is p21 and/or p53 immunoexpression in most cases of this study and there is no clear association between immunoexpression pattern and patient outcome. Unlike the literature, we also found a percentage of nuclear immunostaining, but the finding was not statistically significant. Combination of p21 and p53 results created different possibilities of pathologic interpretation for MH, reinforcing the importance of studies similar to this one.

The current understanding of KRAS protein structure and dynamics.

One of the most common drivers in human cancer is the mutant KRAS protein. Not so long ago KRAS was considered as an undruggable oncoprotein. After a long struggle, however, we finally see some light at the end of the tunnel as promising KRAS targeted therapies are in or approaching clinical trials. In recent years, together with the promising progress in RAS drug discovery, our understanding of KRAS has increased tremendously. This progress has been accompanied with a resurgence of publicly available KRAS structures, which were limited to nine structures less than ten years ago. Furthermore, the ever-increasing computational capacity has made biologically relevant timescales accessible, enabling molecular dynamics (MD) simulations to study the dynamics of KRAS protein in more detail at the atomistic level. In this minireview, my aim is to provide the reader an overview of the publicly available KRAS structural data, insights to conformational dynamics revealed by experiments and what we have learned from MD simulations. Also, I will discuss limitations of the current data and provide suggestions for future research related to KRAS, which would fill out the existing gaps in our knowledge and provide guidance in deciphering this enigmatic oncoprotein.

CIK cell-based delivery of recombinant adenovirus KGHV500 carrying the anti-p21Ras scFv gene enhances the anti-tumor effect and safety in lung cancer.

PURPOSE: Adenovirus (Ads) is one of the most popular vectors used in gene therapy for the treatment of cancer. However, systemic therapy is limited by circulating antiviral antibodies and poor viral delivery in vivo. In this study, we used cytokine-induced killer (CIK) cells as delivery vehicles of Ads KGHV500 carrying the anti-p21Ras scFv gene to treat Ras gene-related lung cancer and investigate the anti-tumor effect in vitro and in vivo. METHODS: The human lung cancer cell line A549 was employed to investigate the anti-tumor activity of recombinant Ads KGHV500 harboring the anti-p21Ras scFv gene using MTT, wound healing, transwell invasion, and apoptosis assays in vitro. Next, CIK cells were used as delivery vehicles to deliver KGHV500 carrying the anti-p21Ras scFv gene to treat A549-transplanted tumors in nude mice, and viral replication, p21Ras scFv expression, and the therapeutic efficacy were assessed. RESULTS: In vitro studies showed that KGHV500 had potent anti-tumor activity. In addition, in vivo, this combination therapy significantly inhibited the growth of lung cancer xenografts compared with mice treated with KGHV500 alone. KGHV500 and anti-p21Ras scFv were observed in tumor tissue, but were nearly undetectable in normal tissues. CONCLUSIONS: The co-delivery of anti-p21Ras scFv by CIK cells and KGHV500 could increase the anti-tumor effect and safety, and possess considerable advantages for the treatment of Ras-related cancer.

Recombinant Adenovirus KGHV500 and CIK Cells Codeliver Anti-p21-Ras scFv for the Treatment of Gastric Cancer with Wild-Type Ras Overexpression.

The development of gastric cancer is frequently related to the overexpression of wild-type p21 proteins, but it is rarely related to mutated Ras proteins. We previously constructed a broad-spectrum anti-p21-Ras single-chain variable fragment antibody (scFv), which was carried by the oncolytic adenovirus KGHV500. Here we explored the antitumor effects of this recombinant oncolytic adenovirus carried by cytokine-induced killer (CIK) cells on human gastric SGC7901 cells that overexpress wild-type Ras. The MTT assay, scratch test, Transwell assay, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed in vitro to investigate the proliferation, migration, invasiveness, and cell apoptosis rate, respectively, of the human gastric cell line SGC7901 treated with KGHV500 adenovirus. Then, the tumor-targeting ability and systemic safety of KGHV500 adenovirus delivered by CIK cells were explored in vivo. We found that KGHV500 adenovirus could significantly inhibit proliferation, migration, and invasiveness and promote cell apoptosis in SGC7901 cells in vitro. In vivo studies showed that CIK cells could successfully deliver KGHV500 adenovirus to the tumor site; the two vectors synergistically killed tumor cells, and the treatment was relatively safe for normal tissues. In conclusion, this therapeutic strategy of recombinant adenovirus KGHV500 delivered by CIK cells offers a positive prospect for the targeted therapy of Ras-related cancers.

Characterization of oncogene suppressor marker expression in patients with submucosal gastric carcinoma.

The aim of the present study was to determine the clinical significance of p53 and p21ras p21wafl, p27kip1 and p16ink4a expression in cases of early gastric cancer. A total of 81 patients who had undergone gastrectomy with D2 lymphadenectomy between 1971 and 2004 were retrospectively investigated. The immunohistochemical expression of p21ras, p53, p21waf1/cip1, p27kip1 and p16ink4a in the tissues was evaluated. In normal, metaplastic and tumoral mucosa, p53 was positive in 53, 87.3, and 87.1% of the cases, respectively. In the same tissues, p21ras was positivE in 85.3, 86 and 96.8%, respectively. Positivity FOR p16ink4a was DETECTED IN 46.3, 91.1 and 86% OF THE CASES, respectively, WHEREAS p27kip1 WAS positiVE IN 60, 94.7 and 95.3%, and p21wafl/cip1 WAS positivE IN 32.4, 72.7 and 71.4% OF THE CASES, respectively. All THE tumors WERE positive for p53. Tumors with lymph node invasion presented WITH OVERexpression (+4) of p53 in 47% of the cases VS. 17% OF patients who DID not HAVE lymph node involvement. THEREFORE, higher expression of p53, p21ras and p21wafl/cip1 IN the tumor exhibited a statistically significant association with lymph node involvement.

S-Nitrosylation of Ras Mediates Nitric Oxide-Dependent Post-Injury Neurogenesis in a Seizure Model.

AIMS: Nitric oxide (NO) is involved in the upregulation of endogenous neurogenesis in the subventricular zone and in the hippocampus after injury. One of the main neurogenic pathways activated by NO is the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway, downstream of the epidermal growth factor receptor. However, the mechanism by which NO stimulates cell proliferation through activation of the ERK/MAPK pathway remains unknown, although p21Ras seems to be one of the earliest targets of NO. Here, we aimed at studying the possible neurogenic action of NO by post-translational modification of p21Ras as a relevant target for early neurogenic events promoted by NO in neural stem cells (NSCs). RESULTS: We show that NO caused S-nitrosylation (SNO) of p21Ras in Cys118, which triggered downstream activation of the ERK/MAPK pathway and proliferation of NSC. Moreover, in cells overexpressing a mutant Ras in which Cys118 was replaced by a serine-C118S-, cells were insensitive to NO, and no increase in SNO, in ERK phosphorylation, or in cell proliferation was observed. We also show that, after seizures, in the presence of NO derived from inducible nitric oxide synthase, there was an increase in p21Ras cysteine modification that was concomitant with the previously described stimulation of proliferation in the dentate gyrus. INNOVATION: Our work identifies p21Ras and its SNO as an early target of NO during signaling events that lead to NSC proliferation and neurogenesis. CONCLUSION: Our data highlight Ras SNO as an early event leading to NSC proliferation, and they may provide a target for NO-induced stimulation of neurogenesis with implications for brain repair. Antioxid. Redox Signal. 28, 15-30.

A Review of Driver Genetic Alterations in Thyroid Cancers.

Thyroid cancer is a frequent endocrine-related malignancy with continuously increasing incidence, and recently the development in understanding its molecular pathogenesis is mainly through the explanation of the original role of several key signaling pathways and related molecular distributors. Central to these mechanisms are the genetic and epigenetic alterations in these pathways such as mutation and DNA rearrangements. However, it does not mean that all the somatic abnormalities in a cancer genome are involved in cancer development and just driver mutations are concerned in tumor initiation. By way of illustrations, MAPK pathway motivated by BRAF V600E and RAS and RET / PTC rearrangements are suggesting driver genetic alterations in follicular derived thyroid cancers considered in the current review.

Effects of miR-1280 expression on the cell cycle and proliferation of bladder cancer by activating p21 gene expression / 国际肿瘤学杂志

Objective To investigate the activation effect of microRNA-1280 (miR-1280) on the expression of p21 gene in bladder cancer cell line BIU-87 and its effect on cell cycle and proliferation of bladder cancer cell line.Methods Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the expressions of miR-1280 in bladder cancer cell lines T24,5637,J82,BIU-87 and normal bladder epithelial cells SV-HUC-1.miR-1280 mimics (experimental group) and miR-NC (control group) were transfected into the bladder cancer cells with the lowest expression of miR-1280.The expressions of miR-1280 and p21 mRNA were detected by qRT-PCR.Chromatin immunoprecipitation (ChIP) was used to verify the targeting effect of miR-1280 and p21 gene promoter.Western blotting was used to detect the expressions of p21,cell cycle-dependent kinase 1 (CDK1),Cyclin A2 mRNA and protein in the two groups.Cell cycle was detected by flow cytometry,and cell proliferation was detected by methyl thiazolyl tetrazclium (MTT) assay.Results The results of qRT-PCR indicated that the expression levels of miR-1280 in bladder cancer cell lines T24,5637,J82 and BIU-87 and normal urothelium cell line SV-HUC-1 were 0.503 ±0.094,0.611 ±0.054,0.567 ± 0.077,0.257 ± 0.032 and 1.014 ± 0.090 respectively,with a significant difference (F =1.880,P ＜0.001).Compared with bladder cancer cell lines T24,5637 and J82 cells,the expression of miR-1280 in BIU-87 cell was the lowest (P =0.026,P =0.003,P =0.008).Compared with the control group,the expression of miR-1280 in BIU-87 cell was significantly increased (1 041.000 ± 157.500 vs.1.023 ± 0.118,t =6.606,P ＜0.001),and the expression of p21 mRNA was also significantly increased (5.280 ± 0.660 vs.1.007 ± 0.070,t =6.440,P ＜ 0.001).Western blotting showed that p21 protein expression was up-regulated,CDK1 and Cyclin A2 protein expressions were down-regulated.ChIP experiments showed that compared with the miR-NC transfection group,the concentration of biotin modified miR-1280 in the p21 gene promoter region was significantly increased (1.246 ±0.171 vs.0.519 ± 0.087,t =3.787,P =0.009).The proportion of G0-G1 cells in the experimental group BIU-87 cells was significantly higher than that in the control group (68.360％ ±3.064％ vs.46.970％ ±3.971％,t =4.263,P =0.005).The results of MTT showed that compared with the control group,the cell proliferation ability of BIU-87 cells after being transfected miR-1280 was significantly decreased starting from day 3 (0.826 ± 0.099 vs.1.224 ± 0.057,t =3.505,P =0.013).Conclusion miR-1280 can activate the expression of p21 gene in bladder cancer cell line BIU-87 by binding the promoter region of p21 gene,blocking the progression of cell cycle and inhibiting cell proliferation,which provides a new direction for bladder cancer targeted therapy theory.

Early and Late Induction of KRAS and HRAS Proto-Oncogenes by Reactive Oxygen Species in Primary Astrocytes.

Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Among mammalian tissues, the highest levels of p21Ras protein are detected in the brain. Here, we investigated the expression of KRAS and HRAS proto-oncogenes in primary astrocytes following acute oxidative stimulation. Reactive oxygen species (ROS) changed the expression of proto-oncogenes at both transcriptional and translational levels. De novo protein synthesis analysis measured approximate values of proteins half-life, ranging from 1-4 h, of the different H- and K- isoforms by western blot analysis. Quantitative gene expression analysis of KRAS and HRAS revealed an unexpected short-term induction of KRAS mRNA in primary astrocytes in response to acute stimulation. Indeed, cultured astrocytes responded to proteasomal inhibition by preventing the reduction of c-K-Ras. A fraction of K-Ras protein accumulated in the presence of ROS and cycloheximide, while a substantial proportion was continuously synthesized. These data indicate that ROS regulate in a complementary fashion p21Ras isoforms in primary astrocytes: K-Ras is rapidly and transiently induced by post-translational and post-transcriptional mechanisms, while H-Ras is stably induced by mRNA accumulation. We suggest that K-Ras and H-Ras are ROS sensors that adapt cells to metabolic needs and oxidative stress.

Regulatory effect of miRNA-370 on expression of tumor suppressor gene p21 in renal cell carcinoma cell lines ACHN and 786-O and its effect on cell growth / 肿瘤研究与临床

Objective To investigate the regulatory effect of miRNA-370(miR-370)on the expression of tumor suppressor gene p21 in renal cell carcinoma cell lines ACHN and 786-O and its effect on cell growth. Methods RCC cells were transfected with dsRNA known lack homology to human genes (control group) and miR-370 (experimental group) by Lipofectamine 3000 respectively. Real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) and Western blot were used to detect the expression of p21 mRNA and protein. The cell cycle distribution was identified by flow cytometry (FCM). Cell viability and proliferation ability were measured by cell viability assay (MTS) and colony culture assay. Results The expression of p21 mRNA in ACTN and 786-O cells in control group was 1.04±0.33, 1.04±0.31, respectively. The expression of p21 mRNA in experimental group was significantly increased by 3.68±0.62 (t=7.535, P<0.001), 3.15±0.29 (t=9.975, P<0.001). Western blot further demonstrated that the increased expression of p21 protein in both renal cell lines was consistent with the upregulation of p21 mRNA level. FCM results showed that the cell cycle of more cells was blocked in G0-G1phase after transfection of miR-370.MTS results showed that after transfection of miR-370,the number of colonies formed by ACHN and 786-O cells in the control group was 113±30 and 106±27 respectively. The number of colonies formed by experimental group was significantly reduced by 53±17 (t=2.982, P=0.041) and 50±16 (t=3.089, P=0.037). Conclusion miR-370 can significantly up-regulate the expression of tumor suppressor gene p21 in renal cell carcinoma and inhibit the growth of renal cell carcinoma.

Regulatory effect of miRNA-370 on expression of tumor suppressor gene p21 in renal cell carcinoma cell lines ACHN and 786-O and its effect on cell growth / 肿瘤研究与临床

Objective To investigate the regulatory effect of miRNA-370(miR-370)on the expression of tumor suppressor gene p21 in renal cell carcinoma cell lines ACHN and 786-O and its effect on cell growth. Methods RCC cells were transfected with dsRNA known lack homology to human genes (control group) and miR-370 (experimental group) by Lipofectamine 3000 respectively. Real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) and Western blot were used to detect the expression of p21 mRNA and protein. The cell cycle distribution was identified by flow cytometry (FCM). Cell viability and proliferation ability were measured by cell viability assay (MTS) and colony culture assay. Results The expression of p21 mRNA in ACTN and 786-O cells in control group was 1.04±0.33, 1.04±0.31, respectively. The expression of p21 mRNA in experimental group was significantly increased by 3.68±0.62 (t=7.535, P<0.001), 3.15±0.29 (t=9.975, P<0.001). Western blot further demonstrated that the increased expression of p21 protein in both renal cell lines was consistent with the upregulation of p21 mRNA level. FCM results showed that the cell cycle of more cells was blocked in G0-G1phase after transfection of miR-370.MTS results showed that after transfection of miR-370,the number of colonies formed by ACHN and 786-O cells in the control group was 113±30 and 106±27 respectively. The number of colonies formed by experimental group was significantly reduced by 53±17 (t=2.982, P=0.041) and 50±16 (t=3.089, P=0.037). Conclusion miR-370 can significantly up-regulate the expression of tumor suppressor gene p21 in renal cell carcinoma and inhibit the growth of renal cell carcinoma.