Interrelationship between chromosome 8 aneuploidy,C-MYC amplification and increased expression in individuals from northern Brazil with gastric adenocarcinoma

AIM: To investigate chromosome 8 numerical aberra- tions, C-MYC oncogene alterations and its expression in gastric cancer and to correlate these findings with histo- pathological characteristics of gastric tumors. METHODS: Specimens were collected surgically from seven patients with gastric adenocarcinomas. Immu- nostaining for C-MYC and dual-color fluorescence in situ hybridization (FISH) for C-MYC gene and chromosome 8 centromere were performed. RESULTS: All the cases showed chromosome 8 aneu- ploidy and C-MYC amplification, in both the diffuse and intestinal histopathological types of Lauren. No significant difference (P < 0.05) was observed between the level ofchromosome 8 ploidy and the site, stage or histological type of the adenocarcinomas. C-MYC high amplification, like homogeneously stained regions (HSRs) and double minutes (DMs), was observed only in the intestinal-type. Structural rearrangement of C-MYC, like translocation, was observed only in the diffuse type. Regarding C-MYC gene, a significant difference (P < 0.05) was observed between the two histological types. The C-MYC protein was expressed in all the studied cases. In the intestinal- type the C-MYC immunoreactivity was localized only in the nucleus and in the diffuse type in the nucleus and cytoplasm. CONCLUSION: Distinct patterns of alterations between intestinal and diffuse types of gastric tumors support the hypothesis that these types follow different genetic path- ways.

Analysis on chromosome 8 heterozygosity loss in humanprostate carcinoma and high grade prostaticintraepithelial neoplasia

Objective: To analysis the chromosome 8 heterozygosity loss in human prostate carcinoma and high grade prostatic intraepithelial neoplasia. Methods: Pure DNA was obtained from prostate neoplasms and normal tissues by tissue microdissection. The chromosome 8 heterozygosity loss was detected by PCR based micro-satellite polymorphism analysis technique using 14 pairs of microsatellite primers in 10 samples of prostate carcinoma and 10 samples of high grade prostatic intraepithelial neoplasia. Results: There were different frequencies of chromosome 8 heterozygosity loss in 10 samples of prostate carcinoma. 8p23.1-p23.2 and p21-p22 were two high frequency heterozygosity loss regions. Chromosome 8 heterozygosity loss was detected in 3 samples of high grade prostatic intraepithelial neoplasia. Conclusion: There were high frequency heterozygosity loss regions on chromosome 8 of prostate carcinoma, located at 8p23.1-p23.2 and p21-p22. The high grade prostatic intraepithelial neoplasia and prostate carcinoma share the same allelic loss on 8p. Tumor suppressor genes located at these two regions may be potentially involved in the initiation and progression of prostate carcinoma.

New mechanism of partial duplication and deletion of chromosome 8:A case report

BACKGROUND During meiosis,the recombination of homologous chromosomes produces some new heritable mutations,which are the basis of biological evolution and diversity.However,when there is pericentric inversion of chromosomes,unbalanced gametes will be formed in the process of germ cell meiosis.CASE SUMMARY A 23-year-old pregnant woman at 25 wk of gestation wanted to terminate her pregnancy due to fetal chromosomal abnormalities.She had no exposure to toxic or hazardous substances before and during pregnancy,no history of medication usage during pregnancy,and she underwent cystectomy of ovarian cysts in 2017.On the second day of the 16th week of gestation,non-invasive prenatal testing showed chromosome 8 copy number variation.Following genetic counseling,her pregnancy was terminated.CONCLUSION Recombinant offspring chromosome is rarely seen when the inversion segment is shorter than one-third of the chromosome length.In terms of the mechanism of chromosome 8 duplication/deletion occurrence,attention should be paid to the production of unbalanced gametes by the pairing of homologous chromosome during meiosis,and the possibility of mitotic recombination exchange as well.

A correlation study between ITGA6 gene,chromosome 8q24,MSMB genes and prostate cancer

Objective To explore the correlation between IT-GA6 gene ( rs12621278, G ) , MSMB gene ( rs10993994,T) ,chromosome 8q24 9 ( rs10086908, T) and prostate cancer ( PCa) in Beijing residents,and to explore the correlation between genotype and pheno-

The predictive value of chromosome 8p deletion for metastasis of hepatocellular carcinoma:a summary of works in 10 years

Hepatocellular carcinoma(HCC)represents an extremely poor prognostic cancer,which is mainly due to the high frequency of metastasis/recurrence after surgical operation.Exploring the molecular mechanisms involved in HCC metastasis could be helpful in the pre-diction and early diagnosis of HCC recurrence and could also provide new therapeutic targets for HCC metastasis.In the recent decade,we analyzed the genomic aberrations of the clinical specimens,as well as the metastatic models and cell lines of human HCC to identify the genetic mar-kers related to HCC metastasis and to verify their clinical values in the prediction and control of metastasis of HCC.Using the comparative genomic hybridization(CGH)technique,we compared the differences of chromosomal aberrations between primary HCC tumors and their matched metastatic lesions,and found that chromosome 8p deletions might contribute to HCC metastasis.This novel finding was further confirmed by comparison between nude mice models of HCC with different meta-static potentials.By the more sensitive genome-wide microsatellite analysis,8p deletion was defined to 8p23.3 and 8p11.2,which are two likely regions harboring meta-stasis-related genes of HCC.Using‘8p-specific’microar-rays,two novel metastatic suppressors(HTPAP and MRSA)were identified,and were proven to suppress in vitro invasion and in vivo metastasis of HCC.Clinical studies indicate that 8p deletion detected in HCC or cir-culating plasma DNA of patients is a useful predictor for metastatic recurrence and prognosis,even for patients with early stage HCC.These novel findings are regarded as important advances in the study of the molecular mechanisms of HCC metastasis,which provide not only a holistic view on the molecular cytogenetic bases of HCC metastasis,but also candidate regions for further study to identify metastatic suppressor genes.

A Panel of Genes Identified as Targets for 8q24.13-24.3 Gain Contributing to Unfavorable Overall Survival in Patients with Hepatocellular Carcinoma

Copy number aberrations （CNAs） in chromosome arm 8q have been associated with unfavorable clinical outcomes of several cancers and progressive tumor characteristics of hepatocellular carcinoma （HCC）. This study was to identify correlation of CNAs in 8q with clinical outcomes of HCC patients, and further screen for differentially expressed genes in outcome-related CNAs. Array comparative genomic hybridization and expression arrays were performed to detect CNAs and expression levels, respectively. The correlations between CNAs in 8q and outcomes were analyzed in 66 patients, with a median follow-up time of 45.0 months （range, 2.6-108.6 months）. One hundred and nine cases were further evaluated to identify differentially expressed genes in the potential outcome-related CNAs. Copy number gain in 8q was observed in 22 （33.3%） of the 66 HCC cases. The most recurrent gains （with frequencies 〉20%） were 8q 13.3-21.3, 8q21.3-23.3, 8q23.3-24.13, 8q24.13-24.3, and 8q24.3. Survival analysis showed that 8q24.13-24.3 gain was significantly associated with reduced overall survival （P=0.010）. Multivariate Cox analysis identified 8q24.13- 24.3 gain as an independent prognostic factor for poor overall survival （HR=2.47; 95% CI=1.16-5.26; P=0.019）. A panel of 17 genes within the 8q24.13-24.3 region, including ATAD2, SQLE, PVT1, ASAP1, and NDRG1 were significantly upregulated in HCCs with 8q24.13-24.3 gain compared to those without. These results suggest that copy number gain at 8q24.13-24.3 is an unfavorable prognostic marker for HCC patients, and the potential oncogenes ATAD2, SQLE, PVT1, ASAP1, and NDRG1 within the regional gain, may contribute coordinately to the 8q24.13-24.3 gain-related poor prognosis.

Combined detection and subclass characteristics analysis of CTCs and CTECs by SE-iFISH in ovarian cancer

Objective:Hematogenous metastasis is essential for the progression of ovarian cancer(OC),and circulating tumor cells(CTCs)are part of the metastatic cascade.However,the detection rate of CTC is low due to the use of less sensitive detection methods.Therefore,this study aimed to detect CTCs and circulating tumorigenic endothelial cells(CTECs)in patients with OC using subtraction enrichment and immunostaining and fluorescence in situ hybridization(SE-iFISH).Methods:We enrolled a total of 56 subjects,including 20 OC patients and 36 ovarian benign tumor patients.CTCs and CTECs were captured by subtraction enrichment(SE)and counted and classified according to immunofluorescence staining of tumor markers(TMs)carbohydrate antigen 125(CA125)and human epididymis protein 4(HE4)combined with fluorescence in situ hybridization(iFISH)of chromosome 8(Chr8)aneuploidy.The diagnostic value and subtype characteristics of CTCs and CTECs were investigated.Results:The detection rate of CTCs by SE-iFISH was high.Compared with CA125 and HE4,Chr8 aneuploidy was the major identification feature of CTC.CTC counts in OC were statistically higher than those in benign groups.CTC and CTEC with≥pentaploidy were detected in both groups,illustrating the poor diagnostic value of CTC or CTEC.Distributions of triploid and tetraploid CTC subtypes were significantly different,and combined detection of triploid and tetraploid CTCs showed the best diagnostic value.In contrast,the distribution of CTECs in the OC and benign groups had no statistically significant difference.Small CTCs accounted for over 1/3 of the total CTC count.We also found that small CTCs and CTECs primarily comprised triploid cells,while large CTCs and CTECs mainly comprised pentaploidy and beyond.Conclusions:The application of SE-iFISH offered a more comprehensive understanding of heterogeneous CTCs and CTECs in OC.Analysis of subclass characteristics of the CTCs and CTECs according to Chr8 aneuploidy and cell size may broaden their potential clinical utility and deepen mechanistic studies in OC.