The Frequency of the v-AKT Murine Thymoma Viral Oncogene Homologue 1 Gene Amplification among Sudanese Women with Ovarian Cancer: A Cross-Sectional Study

Background: Protein kinase B (AKT/PKB) family is frequently amplified in ovarian cancer (OC). To the greatest of our knowledge, there is a lack of published reports about the amplification of the genes belonging to the AKT family among Sudanese women with OC. The present study was conducted to detect the AKT1 gene amplification and its association with tumour types, grades, and ages among Sudanese women with OC, bearing in mind the ethnic variation. Methods: This institution-based study included 79 cases of women diagnosed with ovarian cancer (OC) at Omdurman Maternity Hospital in the period 2013-2018. Formalin-fixed, paraffin-embedded (FFPE) tissue sections were used to extract RNA. AKT1 gene amplification was assessed using quantitative real-time PCR. Results: The mean age (±SD) of included women was 49.29 (±13.612). The amplification of AKT1 gene was observed in 18/79 (22.8%) of OC women, with a high frequency in women with undifferentiated 1/2 (50%), clear cell 2/6 (33.3%), mucinous 3/11 (27.3%), endometrioid 3/17 (17.6%), and serous carcinomas 5/30 OC (16.7%). High frequency was seen in women with low (26.3%;n = 10/28) rather than in higher (19.5%;n = 8/33) grade carcinoma, and in older (25.8%;n = 8/23) rather than younger (18.2%;n = 2/9) women. No significant association between AKT1 gene amplification and tumour types, grades, and ages of women was observed (Fisher’s Exact test: p = 0.405, 0.593 and 0.851, respectively). Conclusion: AKT1 gene amplification arises in around one-fifth of Sudanese women with ovarian cancer (OC). It is seen more in undifferentiated, clear cell, and mucinous tumours types, and more frequently in low tumour grade and older women, but not to a statistically significant level. These outcomes sustenance previous studies suggesting that activated AKT genes have a vital role in OC progression and may offer a plan for targeted therapy and prognostic evaluation.

The role of tazarotene-induced gene 1 in carcinogenesis:is it a tumor suppressor gene or an oncogene?

Tazarotene-induced gene 1(TIG1)is induced by a derivative of vitamin A and is known to regulate many important biological processes and control the development of cancer.TIG1 is widely expressed in various tissues;yet in many cancer tissues,it is not expressed because of the methylation of its promoter.Additionally,the expression of TIG1 in cancer cells inhibits their growth and invasion,suggesting that TIG1 acts as a tumor suppressor gene.However,in some cancers,poor prognosis is associated with TIG1 expression,indicating its protumor growth characteristics,especially in promoting the invasion of inflammatory breast cancer cells.This review comprehensively summarizes the roles of the TIG1 gene in cancer development and details the mechanisms through which TIG1 regulates cancer development,with the aim of understanding its various roles in cancer development.

Study of differential polymerase chain reaction of C-erbB-2 oncogene amplification in gastric cancer

AIM To study the significance of C-erbB-2 oncogene amplification in gastric cancer.METHODS C-erbB-2 oncogene amplification was examined by using differential polymerase chain reaction (dPCR) in surgical and endoscopic specimens of 83 cases of gastric cancer and 101 metastatic lymph nodes.RESULTS C-erbB-2 amplification was found in 28.9% (24/ 83) surgical specimens and 20.5% (17/ 83) endoscopic ones of gastric cancer patients. The amplification was significant in both types of specimens of advanced cancer cases (P＜0.05) and surgical specimens with lymph node metastasis (P＜0.01). The incidence of C-erbB-2 amplification in lymph nodes with metastasis was higher than in primary sites (surgical specimens, P＜0.05). The patients with amplification tumors had poorer 5-year survival rates than those with unamplification ones in the early cancers and well to moderately differentiated adenocarcinomas (P＜0.05). The same surgical samples were tested again by Southern blot hybridization to ascertain C-erbB-2 amplification, and the positive rate of C-erbB-2 amplification (15.7%) was lower than that of dPCR (28.9%, P＜0.05).CONCLUSION Examining C-erbB-2 amplification by dPCR is a quick, simple, reliable and independent method, and is helpful in predicting prognosis and metastatic potential of gastric cancer.

Dual fluorescence in situ hybridization in detection of HER-2 oncogene amplification in primary hepatocellular carcinoma

BACKGROUND: Molecular cytogenetics of oncogene HER-2 amplification in primary hepatocellular carcinoma (HCC) is still unknown. The aim of this study was to in vestigate the frequency of HER-2 oncogene amplification in primary HCC and its relations to clinicopathological pa rameters and prognosis. METHODS: Forty-two surgical samples from patients with primary HCC were detected for their HER-2 oncogene am plification. The number of chromosome 17 and their ratio were tested by dual fluorescence in situ hybridization (FISH) technique, and then the correlations between HER-2 amplification, clinicopathological characteristics and prog nosis were analyzed statistically. RESULTS: HER-2 oncogene amplification was detected in 9 (21.4%) of the 42 primary HCCs, including 4 patient with high copy (HC) (9.5%) and 5 patients with low copy (LC) (11.9%). HER-2 amplification was associated signifi cantly with tumor size and postoperative survival time o HCC patients (P<0.05), and the presence of HER-2 gene amplification was correlated with postoperative relapse (P— 0.257), but not related to sex, age, AFP level, HBV infec tion, histopathological grading and clinical staging of HCC patients (P>0.05). The HER-2 oncogene copy was exa mined in 31 (73.8%) of the 42 primary HCCs, consisting of 9 patients with HER-2 amplification (21.4%) and 22 pa tients with aneuploidy (52.4%). No significant relation were observed between the HER-2 oncogene copy, patien sex, tumor size, histopathological grading, clinical stag ing, postoperative relapse and survival time (P >0.05); bu the HER-2 oncogene copy was correlated significantly to age, AFP level and HBV infection (P <0.05). CONCLUSIONS: There are a lower frequency of HER-2 oncogene amplification and a higher frequency of chromo- some 17 aneuploidy in primary HCC. HER-2 oncogene amplification may be involved in the development and pro- gression of large HCC in some patients, and seems to be a valuably independent prognostic factor predicting the re- currence and poor survival in patients with large HCC.

Oncogenes, Oncogenesis, and Oxygen Radicals

The role that free radicals in general and oxygen radicals in particular play in carcinogenesis has attracted considerable attention in recent years. The oxygen radicals are undesirable but inevitable products of aerobic metabolism in the normal living cell. The cellular antioxidant defense system maintains an appropriate balance between necessary oxidative events and those that are excessive. When this critical balance cannot be maintained because of the overloading of the cellularredox system, oxygen radicals can induce cell damage. They can influence carcinogenesis by inducing DN A damage from direct oxidation or indirectly from DNA-binding products of lipid peroxidation. Oxygen radicals can induce conformational changes in the plasma membrane by lipid peroxidation and protein degradation, thus influencing membrane-associated cellular activities. They are capable of affecting membrane-bound protein kinases, growth factors and their receptors, and, therefore, signal transduction and oncogene activation. Thus, the oxygen radicals can have a major influence on oncogenes and oncogenesis. (C)1990 Academic Press.Inc.

PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

EXPRESSION OF CELLULAR ONCOGENES IN PRIMARY CELLS FROM HUMAN LEUKEMIAS

The expression of three protooncogenes (c-myc, c-fos, N-ras) in.the primary cells from 53 cases of leukemia as well as peripheral WBC from 8 normal individuals was studied. Semiquantitative analysis of mRNA levels of the protooncogenes was carried out by Quick-blot. The results showed that (1) c-myc oncogene was slightly expressed and Nras was marginally expressed, whereas the expression of the c-fos was undetectable in the peripheral leucocytes of 8 normal individuals; (2) the c-myc was obviously expressed in almost all leukemic cells irrespective of the cell types, while N-ras and c-fos were variable expressed; (3) the c-fos was expressed in all 4 cases of M4; (4) the c-myc transcript was detected but the N-ras and c-fos were not in 4 chronic leukemic cases; (5) the relationship between protooncogene expression and state of leukemia or after chemotherapy was also analysed.

INDUCTION OF C-MYC GENE AMPLIFICATION BY HYDROXYUREA AND ITS INHIBITION BY HOMOHARRINGTONINE

Induction of c-myc gene amplification in L1210 cells by hydroxyurea and its inhibition by homohar-ringtonine were investigated using the DNA-DNA molecular hybridization technique. When the cells were treated with hydroxyurea 1.0 mM for 16 hours, and incubated a further 16 hours in a drug-free medium, the c-myc gene amplified 23.5-fold. If homohar-ringtonine 50 μM was used at the same time as hydroxyurea, gene amplification did not occur. Cycloheximide, an inhibitor of protein biosynthesis, produced a similar effect. Our results indicated that a (or some) protein factor(s) might be involved in gene amplification. Detailed analysis showed that the synthesis of this protein factor(s) started 4 hours before the initiation of the S phase but did not continue in the S phase. It was also found that this protein factor(s) was very labile and began to degrade 2 hours after its appearance.

EXPRESSION OF CELLULAR ONCOGENES IN HUMAN PRIMARY HEPATOCELLULAR CARCINOMA

With DNA-mRNA hybridization in situ technique, the expression of five oncogenes, c-N-ras, c-Ki-ras. c-Ha-ras, c-myc and c-fos, was observed in two cases of human hepatocellular carcinoma. The expression of c-N-ras & c-fos was greatly enhanced in tumor tissues of the two cases, and about 25% -50% of the tumor cells showed positive expression. The other three oncogenes namely c-Ki-ras, c-Ha-ras & c-myc, were not detected in these two carcinomas or in the non-cancerous liver tissues adjacent to the carcinomas. It is surmised that c-N-ras and c-fos may play coordinative role in maintaining the malignant phenotype of human primary hepatocellular carcinoma.

THE EXPRESSIONS OF HBV X GENE AND ets-2, IGF-Ⅰ, c-myc AND N-ras ONCOGENES IN HUMAN HEPATOCELLULAR CARCINOMA AND TUMOR-ADJACENT TISSUES

The expressions of HBV X gene and ets-2, IGF-I, c-myc and N-ras were studied in 7 pairs of human primary hepatocellular carcinoma (PHC) and tumor-adjacent tissues, using RNA hybridization and im-munoblot methods. The results showed that specific 17 and 28 kD HBV X gene products (HBxAg) were existed in a portion of PHC and tumor-adjacent tissues. The 17 kD HBxAg was detected in the sera of 3 patients who also had 17 kD HBxAg in their liver tissues. Multiple expressions of oncogenes such as ets-2, c-myc and N-ras were observed in PHC and tumor-adjacent tissues that had HBxAg expressed, indicating HBxAg might function as a transactivator in the course of intracellular proto-oncogene activation. It is also observed that in some tumor-adjacnet tissues the expressions of ets-2, c-myc and N-ras were higher than those in corresponding PHC. The relationship of HBxAg to the expression of est-2, IGF-Ⅱ, c-myc and their possible roles in the carcinogenesis of PHC are discussed.

A study on the activation of 8 oncogenes and inactivation of 2 oncosuppressor genes in human gastric cancer

The changes of 8 oncogenes and 2 oncosuppressor genes in the specimens of cancer-ous and juxtacancerous tissues of 42 cases of gastric cancer were studied with southern blot hy-bridization and PCR-RFLP method.The probes used were c-Ha-ras,K-ras,N-ras,N-myc,c-myc,hst,EGFR,c-erbB-2,p53 and Rb.Amplification,rearrangement and deletion of c-Ha-ras were detected in 8/33 (24.2%) cases of gastric cancer,amplification or rearrangement ofhst and c-erbB-2 in 11/42 (26.2%) and 12/41 (29.2%) cases respectively,amplification ofEGFR in 9/42 (21.4%) cases,and deletion or rearrangement of p53 and Rb in 9/30 (30.0%)and 2/15 (13.3%) cases respectively.Amplification or rearrangement of N-ras (0/33),K-ras(1/26),N-myc (1/26),and c-myc (1/35)was rarely encountered.These findings suggest thatc-Ha-ras,hst,c-erbB-2,EGFR and p53 may be important genes involved in the pathogenesisof gastric cancer.

C-Ha-ras Oncogene in Oral Leukoplakia Tissues

The amplification and the G-T mutation at codon 12 of the C-Ha-ras oncogene in oral leukoplakia tissues were analyzed by using polymerase chain reaction (PCR) and molecular biologic technique. The results showed that these tissues had no amplification of Ha-ras oncogene. Only one case harbored G-T mutation in 11 oral leukoplakias, but this mutation was absent in 10 normal oral mucosal tissues. The possible role and significance of C-Ha-ras oncogene in oral precancerous lesions were also discussed.

Relationship of ultrasonic shear wave velocity with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents

Objective:To discuss the relationship of ultrasonic shear wave velocity (SWV) with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents.Methods:100 patients with primary liver cancer who underwent surgical treatment in our hospital between March 2014 and September 2016 were collected as observation group, and 50 healthy subjects who received physical examination in our hospital during the same period were collected as normal control group. The ultrasonic SWV levels of two groups of subjects were measured before the operation, and the observation groups were further divided into high SWV group and low SWV group, 50 cases in each group. Intraoperative tumor tissue samples were kept and fluorescence quantitative PCR was used to determine the mRNA expression of oncogenes and tumor suppressor genes. Enzyme-linked immunosorbent assay was used to determine serum contents of angiogenesis factors in observation group before operation.Results:Hepatic ultrasonic SWV level in observation group was significantly higher than that in normal control group;proto-oncogene CK, Ki67, Gly-3, Survivin and Pokemon mRNA expression in tumor tissue of high SWV group were higher than those of low SWV group while tumor suppressor genes Tg737, p16, p27, PTEN and runx3 mRNA expression were lower than those of low SWV group;serum angiogenesis factors VEGF, MMP-9 and IGF-1R contents were higher than those in low SWV group. Conclusion: The hepatic ultrasonic SWV level increases in patients with primary liver cancer, and the SWV level is directly correlated with oncogene and tumor suppressor gene expression as well as angiogenesis factor contents.

THE ROLE OF ONCOGENES AND ONCO-SUPPRESSOR GENES IN CARCINOGENESIS

Carcinogenesis is a multi-stage process.This process may involve both genetic and epi-genetic events. Analyses of the involvement ofgenetic events (mutations in the global sensewhich include point mutations, deletions, trans-locations and rearrangements of genetic mate-rial) in carcinogenesis have implicated twomajor classes of genes, oncogenes and onco-suppressor genes. Oncogenes, a term first usedby Huebner and Todaro, are derived by muta-tion of normal cellular genes, protooncogenes.More than 40 oncogenes have now been isolatedand found to encode proteins with diverse bio-chemical functions.

STUDY ON THE RFLPs AND AMPLICATION AND REARRANGEMENT OF THE TRANSFORMING GENES IN PRIMARY HEPATIC CARCINOMA, GASTRIC CARCINOMA AND BRAIN TUMOR WITH SIX HUMAN ONCOGENE PROBES

By using c-Ha-ras-1, N-ras Wigler (left sequence) and P52C.(right sequence), c-sis, v-erbB, c-myc and v-fos oncogenes as probes, restriction fragment length polymorphisms (RFLPs) of tumor tissue DNAs of 95 patients with gastric carcinoma, primary hepatic carcinoma and brain tumor, and those of 90 normal individuals were studied with the techniques of Southern blot and dot blot. Gene amplification and recombination were also examined in some tumors simultaneously. Some alleles of oncogene are reported in Chinese population for the first time. Moreover, the characteristic frequency of some "rare" alleles and genotypes occurred in some tumor samples is significantly higher than that occured in normal individuals. Pedigree analysis for 2 patients showed that some "rare" alleles are also abandant. Besides, gene amplification and recombination were found in some tumors.

Bioinformatics Analysis Revealed Potential Tumor Suppressors (KLF4/CGN), Oncogenes (SHH/LIF) and Biomarkers of Asian Stomach Adenocarcinoma

Stomach adenocarcinoma (STAD) is the fifth most prevalent cancer and the third leading cause of cancer-related death in the world and is more common in Asia than in most Western countries. There is an urgent need to identify potential novel oncogenes and tumor suppressor genes, and biomarkers for STAD. 6652 differentially expressed genes were identified between STAD and normal samples based on the transcriptome data analysis of the TCGA and GEO databases. 13 key modules were identified in STAD by WGCNA analysis. 293 potential STAD associated genes were identified from intersection by Venn Diagram. The 293 intersected genes were enriched in cell cortex and infection by GO and KEGG analysis. 10 hub genes were identified from PPI and Cytoscape analyses of the intersected genes. KLF4/CGN low and SHH/LIF high expression were associated with short overall survival of Asian STAD patients. Bioinformatics analysis revealed potential novel tumor suppressors (KLF4/CGN), oncogenes (SHH/LIF) and biomarkers for diagnosis, therapy and prognosis of STAD, specifically for Asian patients.

DIFFERENCES IN EXPRESSION AND REGULATION BETWEEN TRANSFORMED CELLS OF THE HUMAN GASTRIC CARCINOMA ONCOGENE Ha-ras AND THE UNTRANSFORMED PARENT CELLS

An Ha-ras oncogene was isolated from a cell line of gastric carcinoma called BGE-823 in order to elucidate genetic control and the influence of DNA sequences. The oncogene was cloned and identified as a single nucleotide substitution of thymine for guanine in the 12th codon through the sequencing of its first axon. We compared the differences of expression and regulation between the transformed Ha-ras cells and untransformed parent cells. Data indicated that the expression of Ha-ras in the transformed cells was five-fold higher than in the untransformed cells and that the Ha-ras gene in the former was hypersensitive toward DNase I. In addition, a nuclear protein of 35 kilodaltons bound strongly to the 2.5 Kb fragment located upstream of the 6.6 Kb Ha-ras gene and contained a CC rich region. These results suggest that there might be another mechanism of activation for the ras gene besides point mutation.

Correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression

Objective: To investigate the correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression. Methods: A total of 91 patients with breast cancer and 85 patients with breast adenoma who accepted surgical treatment in our hospital between August 2016 and February 2018 were selected, and the breast cancer tissues and breast adenoma tissues were collected respectively as the research samples. Fluorescence quantitative PCR method was used to detect the expression of Kif2a and HPK1 genes as well as oncogenes and drug resistance genes in sample tissues, and Pearson test was used to evaluate the inner link of Kif2a and HPK1 gene expression in breast cancer tissue with oncogene and drug resistance gene expression. Results: Kif2a mRNA expression in breast cancer tissues was higher than that in breast adenoma tissues whereas HPK1 mRNA expression was lower than that in breast adenoma tissues;oncogenes DEK, iASPP-SV, Stat3, MDM2 and Fra-1 mRNA expression were higher than those in breast adenoma tissues;drug resistance genes ESR1, MDR1, P-gp, MRP1 and GST- mRNA expression were higher than those in breast adenoma tissues whereas BCRP mRNA expression was lower than that in breast adenoma tissues. Correlation analysis showed that the Kif2a and HPK1 gene expression in breast cancer tissues were directly correlated with the expression of oncogenes and drug resistance genes. Conclusion: Kif2a gene is abnormally highly expressed whereas HPK1 gene is abnormally lowly expressed in breast cancer tissues, and they are involved in the regulation of oncogene and drug resistance gene expression.

Correlation of small hepatocellular carcinoma ultrasonography parameters with the expression of oncogenes and angiogenesis genes

Objective: To investigate the correlation of small hepatocellular carcinoma ultrasonography parameters with the expression of oncogenes and angiogenesis genes. Methods: A total of 61 patients with small hepatocellular carcinoma who were diagnosed in this hospital between July 2015 and May 2017 were selected as small hepatocellular carcinoma group, and 48 patients with hepatolithiasis were selected as hepatolithiasis group. The ultrasonography parameters of the two groups were recorded and the expression levels of oncogenes and angiogenesis genes in the surgical lesion tissues were detected. Pearson test was used to evaluate the correlation of ultrasonography parameters with the expression of oncogenes and angiogenesis genes. Results: IMAX level in small hepatocellular carcinoma group was higher than that in hepatolithiasis group while TTP and mTT levels were lower than those in hepatolithiasis group;oncogenes C-myc, N-ras, PIK3CA, RMP, Bmil and pim-3 mRNA expression in lesion tissues were higher than those of hepatolithiasis group;angiogenesis genes VEGF, Ang-1, Tie-2 and MACC1 mRNA expression in lesion tissues were higher than those of hepatolithiasis group while ARH1 mRNA expression was lower than that of hepatolithiasis group. Pearson test showed that the ultrasonography parameters IMAX, TTP and mTT levels in patients with small hepatocellular carcinoma were directly correlated to the expression of oncogenes and angiogenesis genes in lesions. Conclusion: The ultrasonography parameters of patients with small hepatocellular carcinoma are significantly different from those of patients with benign diseases, and the specific parameter levels are directly correlated with the malignancy of cancer cells.

Estrogen receptor alpha gene amplification in breast cancer:25 years of debate

Twenty-five years ago,Nembrot and colleagues reported amplification of the estrogen receptor alpha gene(ESR1) in breast cancer,initiating a broad and still ongoing scientific debate on the prevalence and clinical significance of this genetic aberration,which affects one of the most important genes in breast cancer.Since then,a multitude of studies on this topic has been published,covering a wide range of divergent results and arguments.The reported prevalence of this alteration in breast cancer ranges from 0% to 75%,suggesting that ESR1 copy number analysis is hampered by technical and interpreter issues.To date,two major issues related to ESR1 amplification remain to be conclusively addressed:(1) The extent to which abundant amounts of messenger RNA can mimic amplification in standard fluorescence in situ hybridization assays in the analysis of strongly expressed genes like ESR1,and(2) the clinical relevance of ESR1 amplification:Such relevance is strongly disputed,with data showing predictive value for response as well as for resistance of the cancer to anti-estrogen therapies,or for subsequent development of cancers in the case of precursor lesions that display amplification of ESR1.This review provides a comprehensive summary of the various views on ESR1 amplification,and highlights explanations for the contradictions and conflicting data that could inform future ESR1 research.