Modern methods of prostate cancer diagnostics

The review highlights analytic capacities of immunochemical and molecular-genetic methods used in the non-invasive test for prostate cancer and monitoring of efficacy of anticancer therapy. The perspectives of their applications in clinical practice also have been evaluated.     

Breast cancer diagnostics based on extracellular DNA and RNA circulating in blood

Extracellular DNA and RNA were extracted from blood plasma and cell surface-bound fractions of healthy women and patients with fibroadenoma and breast cancer. Frequency of methylation of RASSF1A, Cyclin D2, and RARβ2 genes was detected in the extracellular DNA using methylation-specific PCR. Methylation of at least one of these genes was found in plasma of 13% patients with nonmalignant breast fibroadenoma and in 60% of breast cancer patients. Employment cell-surface bound DNA as the substrate for PCR increased the detection frequency of gene methylation up to 87% in patients with fibroadenoma and 95% in breast cancer patients. In clinically healthy women the methylation markers have not been found in extracellular DNA. GAPDH, RASSF8, Ki-67 mRNAs, and 18S rRNA copies were quantified using RT-qPCR of extracellular RNA circulating in blood of patients with breast tumors and healthy controls. The major part of blood extracellular RNA is associated with cell surface. ROC analysis has shown that differences in concentrations 18S RNA, RASSF8, and Ki-67 mRNAs in blood plasma are highly sensitive and specific in discrimination of benign and malignant breast tumors. Thus, analysis of methylated forms of tumor suppressor genes in blood extracellular and quantification of specific extracellular RNA circulating in blood plasma may detect mammary gland tumors and discriminate malignant and benign neoplasms.     

The correlation between pre-operative serum tumor markers and lymph node metastasis in gastric cancer patients undergoing curative treatment

Abstract

Background: There was few study concentrated on the correlation between the evaluated tumor markers and lymph node metastasis. In this study, we aimed to evaluate the correlation between the CA724, CA242, CA199, CEA and the lymph node metastasis of gastric cancer and assess the prognostic value of them in different N stage patients.

Methods: We analyzed the correlation between serum level of CA724, CA242, CA199, CEA and lymph node metastasis in 1501 gastric cancer patients.

Results: Lymph node metastasis of gastric cancer was related with tumor location, Bormann type, tumor size, histological type, depth of invasion and TNM stage (p?<?0.05). The values of CA724, CA242, CA199 and CEA were positively correlated with the metastatic lymph node counts and the N stage (p?<?0.05). The later the N stage was, the levels of CA724, CA242 and CA199 were higher. The later the N stage was, the positive rates of tumor markers were higher (p?<?0.05). In comparing with single tumor markers, the positive rates of tumor markers combination were higher. The combination of CA724?+?CA242?+?CA199?+?CEA had highest positive rate. The higher CEA level related to N1 stage patients while higher CA199 was related with poor prognosis for N1 stage patients. For N0 and N2 stage patients, evaluation of CA724 indicated poorer prognosis. For N1 and N2 stage gastric patients, the patients with increased CA242 inclined to have shorter survival time.

Conclusions: The tumor makers CA724, CA242, CA199 and CEA were evaluated significantly in the gastric patients with later N stage. The combination of these four tumor markers maybe prefer diagnostic index of gastric cancer and its lymph node metastasis. These tumor markers can be a possible indicator of poorer prognosis in different N stage patients.     

Plasma levels and diagnostic utility of VEGF,MMP-2 and TIMP-2 in the diagnostics of breast cancer patients

Objective: We investigated plasma levels and diagnostic utility of vascular endothelial growth factor VEGF, matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinase-2 (TIMP-2) in comparison to cancer antigen 15-3 (CA 15-3).

Methods: Plasma levels of tested parameters were determined using enzyme-linked immunosorbent assay (ELISA) while CA 15-3 with chemiluminescent microparticle immunoassay (CMIA).

Results: The plasma levels of VEGF, TIMP-2 showed significantly higher than CA 15-3 values of the diagnostic sensitivity, the predictive values of positive and negative test results (PPV, NPV) and the area under the receiver-operating characteristics (ROC) curve (AUC) in early stages of breast cancer (BC). The combined use of the tested parameters with CA 15-3 resulted in the increase in sensitivity, NPV and AUC, especially in the combination with VEGF (83%; 72%; 0.888) and TIMP-2 (83%; 72%; 0.894). The highest values were obtained for combination of all three parameters (93%; 85%; 0.923).

Conclusions: These findings suggest the usefulness of the tested parameters in the diagnosis of BC, especially VEGF and TIMP-2 with CA 15-3 in early stages of BC, which could be a new diagnostic panel.     

Tumor microenvironment characterization in stage IV gastric cancer

Immunotherapy is remarkably affected by the immune environment of the principal tumor. Nonetheless, the immune environment’s clinical relevance in stage IV gastric cancer (GC) is largely unknown. The gene expression profiles of 403 stage IV GC patients in the three cohorts: GEO (Gene Expression Omnibus, {"type":"entrez-geo","attrs":{"text":"GSE84437","term_id":"84437"}}GSE84437 (n=292) and {"type":"entrez-geo","attrs":{"text":"GSE62254","term_id":"62254"}}GSE62254 (n=77), and TCGA (The Cancer Genome Atlas, n=34) were used in the present study. Using four publicly available stage IV GC expression datasets, 29 immune signatures were expression profiled, and on this basis, we classified stage IV GC. The classification was conducted using the hierarchical clustering method. Three stage IV GC subtypes L, M, and H were identified representing low, medium, and high immunity, respectively. Immune correlation analysis of these three types revealed that Immune H exhibited a better prognostic outcome as well as a higher immune score compared with other subtypes. There was a noticeable difference in the three subgroups of HLA genes. Further, on comparing with other subtypes, CD86, CD80, CD274, CTLA4, PDCD1, and PDCD1LG2 had higher expression in the Immunity H subtype. In stage IV GC, potentially positive associations between immune and pathway activities were displayed, due to the enrichment of pathways including TNF signaling, Th-17 cell differentiation, and JAK-STAT signaling pathways in Immunity H vs Immunity L subtypes. External cohorts from TCGA cohort ratified these results. The identification of stage IV GC subtypes has potential clinical implications in stage IV GC treatment.     

胃癌发生中的独特肿瘤标记物—LI-cadherin

LI-cadherin,也被称为cadherin-17,是肠上皮细胞中一种贯穿细胞膜的、钙依赖性的、介导细胞间连接的糖蛋白。与经典钙黏蛋白相比,LI-cadherin是一种具备独特结构和功能的新型钙黏蛋白。LI-cadherin由7个胞外重复序列和一个只包含20个氨基酸残基的较短的胞质尾区组成。在人体中,LI-cadherin特异性的位于肝细胞和肠细胞中的底外侧区。而LI-cadherin介导细胞连接时,既不与链蛋白结合,也不导致β-catenin的上调。一些研究发现,在胃癌中LI-cadherin的过度表达与CDX-2显著相关,而且在肠化生中CDX-2的表达总是与LI-cadherin呈现很强的成对性。最新的研究认为LI-cadherin的表达与胃癌的发生、发展、转移及预后均有关系。在针对胃癌的临床处理方面,LI-cadherin将会是有用的肿瘤标记物。     

Exosomal miRNAs as circulating biomarkers for prediction of development of haematogenous metastasis after surgery for stage II/III gastric cancer

Exosomes secreted by living cancer cells can regulate metastasis. Exosomal miRNAs can reflect pathological conditions of the original cancer cells. Therefore, we aim to identify exosomal miRNAs as circulating biomarkers for haematogenous metastasis of gastric cancer. Pre-treatment serum samples of eighty-nine patients with stage II/III gastric cancer were collected. Thirty-four of them developed haematogenous metastasis after surgery and the other fifty-five did not. Extraction of exosomes was validated by western blot, transmission electron microscopy and nanoparticle tracking analysis. MiRNA qPCR array was performed in three matched pairs of samples. Internal control was selected from PCR array and validated in the remaining samples. Expressions of exosomal miRNAs were evaluated in the remaining samples by RT-qPCR, as well as in gastric cancer tissue samples and cell culture medium. Expression levels of exosomal miRNAs were analysed with clinical characteristics. The results indicated thirteen up-regulated and six down-regulated miRNAs were found after normalization. MiR-379-5p and miR-410-3p were significantly up-regulated in metastatic patients (P < .01). Higher expression of exosomal miR-379-5p or miR-410-3p showed shorter progression-free survival of the patients (P < .05). It was also found that miR-379-5p and miR-410-3p were down-regulated in gastric cancer tissue samples, while they were significantly up-regulated in gastric cancer cell culture medium compared with cancer cells. In conclusion, exosomal miRNAs are promising circulating biomarkers for prediction of development of haematogenous metastasis after surgery for stage II/III gastric cancer.     

SRPK1 facilitates tumor cell growth via modulating the small nucleolar RNA expression in gastric cancer

Serine-arginine protein kinase 1 (SRPK1) is the main regulator in alternative splicing by phosphorylating splicing factors rich in serine/arginine repeats. Its overexpression has been found in multiple cancer types and contributes to cancer development. Here we report the role of SRPK1 and underlying mechanism in gastric cancer (GC) cell growth. We found that SRPK1 was frequently upregulated in GC samples compared with their adjacent corresponding normal tissues by immunohistochemistry and western blot analysis. Knockdown of SRPK1 in GC cells suppressed cell growth in cell viability assays, colony formation assays and nude mice xenograft model, whereas overexpression of SRPK1 promotes opposite phenotypes in these assays. By a complementary DNA microarray analysis, we found that SRPK1 knockdown had significant inhibitory effects on a majority of small nucleolar RNAs expression. Among them, snoRA42, snoRA74A, and snoRD10 were selected for further functional experiments. Cell growth curves on a plate and in soft agar indicated that the three snoRNAs play potential oncogenic function in GC. In addition, SRPK1 could co-immunoprecipitated with NCL, a nucleolar phosphoprotein involved in the synthesis and maturation of ribosomes. These results suggested that SRPK1 contributes to GC development by a new possible mechanism involving snoRNAs mediated signaling.     

CTNNBIP1 downregulation is associated with tumor grade and viral infections in gastric adenocarcinoma

Gastric cancer is a life-threatening disease; resulting from interaction among genetic, epigenetic, and environmental factors. Aberrant dysregulation and methylation changes in Wnt/β-catenin signaling downstream elements are a prevalent phenomenon encountered in gastric tumorigenesis. Also, viral infections play a role in gastric cancer development. CTNNBIP1 (β-catenin interacting protein 1) gene is an antagonist of Wnt signaling which binds to the β-catenin molecules. The CTNNBIP1 function as tumor suppressor gene or oncogene in different types of cancer is controversial. Moreover, its function and regulatory mechanisms in gastric cancer progression is unknown. In the present study, we examined CTNNBIP1 gene expression, the methylation status of the regulatory region of the gene, and their association with Epstein–Barr virus (EBV), and cytomegalovirus (CMV) and Helicobacter pylori infections in human gastric adenocarcinoma tissues in comparison with their adjacent nontumoral tissues. Our data revealed a significant downregulation of CTNNBIP1 in gastric tumors. Female patients showed lower level of CTNNBIP1 than males (p < 0.05). Also, decreased expression of CTNNBIP1 was markedly associated with well-differentiated tumor grades (p < 0.05). No methylation change was observed between tumoral and nontumoral tissues. Additionally, CTNNBIP1 down regulation was significantly associated with CMV infection (p < 0.05). In the absence of EBV infection, lower expression of CTNNBIP1 was observed. There was no association between H. pylori infection and CTNNBIP1 expression. Our findings revealed the tumor suppressor role for CTNNBIP1 in gastric adenocarcinoma. Interestingly, EBV and CMV infections modulate CTNNBIP1 expression.     

Presence of cancer cells in gastric lavage of gastric cancer patients as an indicator of advanced disease,predictor of tumour aggressive phenotype and independent prognostic factor for poor survival: The endoluminal metastatic pathway of gastric cancer and GL0/GL1 classification

Objective

As of 2017, the pathobiology of gastric cancer (GC) is far from fully understood; consequently, new methods of basic and advanced research have been proposed and tested. The presence (GL1) vs absence (GL0) of malignant cells exfoliated in gastric lavage (GL) of GC patients was formerly evaluated with diagnostic intent but not for staging or prognostic assessment. We investigated this hitherto unreported application of cytopathology.

Methods

GL was preoperatively and prospectively collected from 80 GC patients and cytologically analysed. The results were compared with the classic clinicopathological features of GC and related to survival. The prognostic value of GL1 was assessed through univariate and multivariate analyses.

Results

GL1 was detected in 36 samples (45%) and correlated with advanced tumour depth (T3‐T4), lymphatic metastasis (N+), distant metastasis (M1) and lymphovascular invasion (LVI1; P=.0317, .0024, .003 and .0028, respectively). Overall survival (OS) was significantly shorter for GL1 (23 months) vs GL0 patients (42 months; P=.005) and GL1 vs GL0 T1 subjects (12.6 vs 47.8 months, P=.0029). Univariate analysis revealed that GL1, N+, M1, LVI1 and advanced stage were significantly associated with OS. Multivariate analysis assessed GL1 as the only independent prognostic factor for worse OS and progression‐free survival (P=.0013 and .0107).

Conclusions

In the present study, GL1 was correlated with advanced disease, aggressive tumour behaviour and poor prognosis. Although additional studies are needed to confirm these findings, the GL0/GL1 classification can be applied to GC patients to achieve higher accuracy in staging, prognostic stratification and treatment selection.     

Rapid induction of apoptosis in human gastric cancer cell lines by sorbitol

Most solid tumors, including gastric cancers, respond poorly to non-surgical treatments which are expected to induce an apoptosis-dependent involution. We hypothesize that the apoptotic machinery in solid tumors is either defective or in a suppressed condition. Overcoming the ineffective induction of apoptosis may improve the responsiveness of solid tumors to non-surgical treatments. Recently, sorbitol, a kind of hexose, has been found to be an effective inducer of apoptosis in HEp-2 cells. Therefore, it is of particular interest to examine the effect of sorbitol-treatment on gastric cancer cells. In the present study, we selected 4 gastric cancer cell lines which have been reported to exhibit different abilities in regard to apoptosis induction, and examined the effect of sorbitol-treatment on apoptosis induction. Within 3 hr after sorbitol-treatment, apoptosis was induced comparably in all cell lines examined. Cell death in MKN-1, MKN-28 or MKN-74 proceeded in a biphasic manner, while cell death in KATO-III was monophasic. The cell death partially depended on caspase activity. Treatments with sorbitol in combination with 12-O-tetradecanoylphorbol-13-acetate (TPA) markedly suppressed the apoptotic cell death, suggesting a role of protein kinase-C-dependent process. To our knowledge, this is the most rapid induction of apoptosis in human gastric cancer cells reported to date.     

CpG island hypermethylation of tumor-suppressor genes in H. pylori-infected non-neoplastic gastric mucosa is linked with gastric cancer risk

Background and aim: Gastric carcinogenesis involves CpG island hypermethylation (CIHM) of tumor‐suppressor genes. Although the CIHM of these genes occurs in non‐neoplastic gastric cells, it is unclear whether this epigenetic alteration is linked with aging and/or gastric cancer risk. We investigated this linkage in noncancerous gastric mucosa infected with H. pylori. Subjects and methods: Noncancerous corpus mucosa was endoscopically obtained from H. pylori‐positive gastric cancer patients (n = 34), and age‐matched H. pylori‐positive noncancerous controls (n = 68). Genomic DNA retrieved from the mucosa was subjected to methylation‐specific polymerase chain reaction for p16, Ecad, and DAPK genes. Linkage between CIHM and clinicopathologic factors was evaluated. Results: CIHM rates of DAPK, Ecad, and p16 promoters were significantly higher in noncancerous gastric mucosa of gastric cancer patients (91, 88, and 68%, respectively) than in noncancerous controls (71, 53, and 25%, respectively). Multivariate regression analysis showed a significant linkage between CIHM in noncancerous mucosa and coexistence of gastric cancer. Significant linkage between polymorphoneutrophil infiltration and CIHM was observed except for CIHM of p16. No linkage was observed between CIHM and other parameters, including age. High CIHM status (all three tested genes methylated) was associated with an increased risk of gastric cancer, with an odds ratio of 9.8 (95% confidence interval, 3.8–25.3). Conclusions: In a subset of the H. pylori‐infected population, CIHM of tumor‐suppressor genes in noncancerous gastric mucosa is linked with the risk of gastric cancer and polymorphoneutrophil infiltration, but not aging. CIHM is a potential marker of gastric cancer risk.     

Latent structure of dermatoglyphics in gastric cancer patients

Gastric cancer is a very common malignant disease, which etiology is still unknown. It is believed that it is caused by a joint activity of both genetic and environmental factors. Gastric cancer between relatives in some families is almost four times higher and in connection with truncating mutations in the E-cadherin gene. The Helicobacter pylori are also established carcinogen and this infection increases the cancer risk by about 5 times. Digito-palmar dermatoglyphics have already been used for determining hereditary base of some malignant diseases (breast, lung, colorectal cancer etc.), which was the encouragement to investigate the latent structure in patients with gastric cancer (36 males and 32 females) and the control groups (50 males and 50 females). The factor analysis has shown that in both males and females with gastric cancer 5 factors were extracted and in males 77.17% and in females 78.92% of total variance was explained, and this result is different from control group where in males 5 factors and 75.97% of total variance were explained while in control females 6 factors and 82.86% of total variance were explained. The finger ridge counts are extracted on the first factor in all groups. In patients the second factor is formed by the first, fourth and fifth fingers, while in controls mostly by palmar variables. From the obtained findings it can be concluded that the results of latent structure in quantitative analysis of digito-palmar dermatoglyphics are affirming the existence of genetic differences in patients suffered with gastric cancer.     

Long noncoding RNAs expression in gastric cancer

Long noncoding RNAs (lncRNAs) have been involved in the pathogenesis of several human cancers including gastric cancer. In the current study, we selected five lncRNAs namely NEAT1, TUG1, PANDA, UCA1, and GHET1 to assess their expressions in gastric cancer samples compared with adjacent noncancerous tissues (ANCTs) from the same patients. Some previous reports have shown contribution of these lncRNAs in gastric cancer. However, we aimed to explore their associations with patients’ clinicopathological data and their potential as diagnostic biomarkers. Significant associations were found between site of primary tumor and relative expression of all lncRNAs in cancer samples compared with ANCTs. Besides, GHET1 relative expression was associated with lymph node status. The diagnostic power of GHET1 was higher from other lncRNAs. Combination of GHET1, TUG1, UCA1, and PANDA increased the diagnostic power and significance (AUC = 0.8; P < 0.0001). The current study supports participation of lncRNAs in the pathogenesis of gastric cancer and highlights their potential as diagnostic biomarkers.     

Genetic polymorphisms of XRCC1 gene and susceptibility to gastric cancer in Chinese Han population

Abstract

This study aims to evaluate whether the c.1471G?>?A and c.1686C?>?G genetic polymorphisms of XRCC1 gene influencing gastric cancer susceptibility. A total of 813 subjects with Chinese Han ethnicity were enrolled. Our data suggest that the allele and genotype frequencies are significantly different from gastric cancer patients with cancer-free controls. We find that c.1471G?>?A and c.1686C?>?G genetic polymorphisms statistically increase the risk of gastric cancer. Our findings indicate these two genetic polymorphisms are related with the susceptibility to gastric cancer, and could be used as molecular markers for detecting gastric cancer in Chinese Han ethnicity.