Clinical significance of MET gene amplification in metastatic or locally advanced gastric cancer treated with first-line fluoropyrimidine and platinum combination chemotherapy

Objective: To investigate the clinical significance of MET gene amplification in patients with gastric cancer in the palliative setting.Methods: MET amplification was assessed using fluorescence in situ hybridization(FISH) in 50 patients and quantitative polymerase chain reaction(qPCR) in 326 patients;259 patients treated with first-line fluoropyrimidine and platinum were included for survival analysis.Results: The results of FISH and qPCR indicated that the c-MET/CEP7 ratio was correlated with gene copy number. The optimal cutoff value for the copy number using qPCR to detect MET gene amplification with FISH was 5(κ=0.778, P<0.001). Twenty-one out of 326 patients(6.4%) were identified as MET amplification with a copy number of >5 detected by qPCR. MET-amplified gastric cancer was associated with an Eastern Cooperative Oncology Group(ECOG) performance status(PS) score of ≥2(33.3% vs. 10.5% P=0.007), peritoneal metastasis(76.2% vs. 46.2%, P=0.008), and elevated bilirubin levels(28.6% vs. 7.3%, P=0.006). The median overall survival(OS) and progression-free survival(PFS) were 11.9 and 5.6 months, respectively. MET-amplified gastric cancer was not associated with survival outcomes [hazard ratio(HR)=0.68, 95% confidence interval(95% CI): 0.35-1.32,P=0.254 for PFS;HR=0.68, 95% CI: 0.35-1.32, P=0.251 for OS].Conclusions: qPCR can be used to detect MET gene amplification. MET amplification was not a predictor of poor prognosis in patients with metastatic or unresectable gastric cancer.

Synchronous Detection of DNA/RNA of Four Shrimp Viruses by Real-time Fluorescence Quantitative RT-PCR

[ Objective] This study aimed to establish a simultaneous detection method of shrimp viruses by real-time fluorescence quantitative RT-PCR, to improve the efficiency of inspection and quarantine. [ Method] A novel real-time fluorescence quantitative RT-PCR assay was established and optimized for simultaneously detecting DNA/RNA of four shrimp viruses （WSSV, IHHNV, TSV and YHV ）. [ Result] The optimized real-time fluorescence quantitative RT-PCR system gener- ated typical amplification curves with high amplification efficiencies （E = 1.06, 1.07, 0.92 and 0.92, respectively）, good hnear relationship （ r = 1 ）, uniform repeatability （ standard deviation = 0.05 - 0.46 ; variation coefficient = 0.26% - 1.62% ） and high sensitivity, exhibiting no significant differences compared with re- al-time fluorescence quantitative PCR （average error of Ct value = 0.04 -0.40; T = 0.53 -2.50; P 〉 0.05 ）. The total detection time was about 1 h. [ Conclusion] The optimized real-time fluorescence quantitative RT-PCR system can be used for rapid detection of WSSV, IHHNV, TSV and YHV.

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.

A LFD-RAA-Based Rapid Detection Method for Pseudomonas syringae pv. tabaci

This study aimed to achieve rapid detection of Pseudomonas syringae pv.tabaci,the pathogen of tobacco wildfire disease.The specific primers and probes for recombinase-aided amplification(RAA)were designed with HrpZ as the target gene.RAA was then combined with the lateral flow dipstick(LFD)to establish a LFD-RAA-based rapid detection system for the pathogen.Furthermore,the detection performance of the established method was tested.The results showed that the LFDRAA method had high specificity.The amplification could be completed after 25 min of reaction at 39℃.The sensitivity of the established method reached 0.0001 ng/μL,which was superior to that of PCR detection.Moreover,the LFD-RAA method could quickly detect P.syringae pv.tabaci from tobacco leaves,demonstrating field applicability.To sum up,the LFD-RAA method established in this study can be applied in the rapid detection and early diagnosis of tobacco wildfire disease.

Cloning and characterization of the gene encoding an ubiquitin-activating enzyme E1 domain-containing protein of silkworm, Bombyx moil

Bombyx mori cytoplasmic polyhedrosis virus （BmCPV） is one of the major viral pathogens for the silkworm. To date, the molecular mechanism of BmCPV invasion has been unclear. We cloned the full length complementary （c）DNA which encodes the ubiquitin-activating enzyme El-domain containing proteinl （UbE1DC1） ofBombyx mori by using suppression subtraefive hybridization （SSH） and rapid amplification of com- plementary （c）DNA ends （RACE）. The full-length eDNA of UbE1DClgene is 1 919 bp, consisting of a 100 bp 5＇ untranslated region, a 637 bp 3＇ untranslated region and an 1 182 bp open reading frame （ORF）, encoding a 393 amino acid protein. The protein contained the THiF_MoeB_hesA_family domain, an adenosine triphosphate binding site, which belongs to the family of ubiquitin-activating enzyme El. Reverse transcription - polymerase chain reaction analysis from the silkworm tissues, namely silk gland, hemo- cyte, fat body, gonad and midgut revealed that UbE1DC1 was expressed in all the five tissues. The real-time quantitative polymerase chain reaction analysis indicated that the relative expression of UbE1DC1 in the normal midgut was approximately 9.78-fold of that in the BmCPV-infected midgut. It is implicated that UbEIDCI may play an important role in the interaction between the host and BmCPV invasion.