PARP1: A potential biomarker for gastric cancer

Gastric cancer (GC) is the third leading cause of cancer mortality worldwide, with an overall 5-y survival rate of 25%. The majority of GCs are caused by infectious agents, including the bacterium Helicobacter pylori (H. pylori) and Epstein–Barr virus (EBV). Furthermore, inappropriate repair of DNA damage can also result in genomic instability, which has shown to be a key factor in carcinogenesis of different regions including gastric region. Present study was designed to explore the association between base excision repair pathway genes, PARP1 and APEX1 and gastric pathology and H. pylori infection. Two hundred gastric cancer tissue samples (114 H. pylori positive and 86 H. pylori negative) and adjacent uninvolved area taken as controls was used for expression analysis of BER pathway genes at mRNA level and protein levels using quantitative PCR (qPCR) and immunohistochemistry (IHC) respectively. Oxidative stress and DNA damage was also determined by measuring the level of antioxidant enzymes and comet assay respectively. Significant upregulation in PARP1 (p < 0.001) and APEX1 (p < 0.02) was observed in GC tissue samples compared to controls and this upregulation was more pronounced in H. pylori positive cases (HPGC) (PARP1, p < 0.02: APEX1, p < 0.04) than H. pylori negative cases (HNGC). Upregulation of BER pathway genes in HPGC was found correlated with smoking status (p < 0.0001), T stage (p < 0.01) and lymph node metastasis (p < 0.03). Moreover, immunohistochemical staining of BER pathway genes was found correlated with a number of clinicopathological characteristics such as tumor type (p < 0.03), tumor size (p < 0.01) and lymph node metastasis (p < 0.01). Expression levels of APEX1 and PARP1 gene also correlated with increased oxidative burden (p < 0.0001) and DNA damage (p < 0.001) in GC patients. Survival analysis showed that upregulation of PARP1 gene was associated with poor overall survival outcome of gastric cancer patients (HR = 2.04 (95% CI = 1.10–3.76; p < 0.02). Univariate and multivariate cox regression analysis showed the upregulated PARP1 gene (HR = 5.03; 95%CI (2.22–11.35); p = 0.0001), positive smoking status (HR = 3.58; 95%CI (1.67–7.65); p = 0.001), positive status for H pylori infection (HR = 4.38; 95%CI (1.82–10.56); p = 0.001) and advance N-stage (HR = 5.29; 95%CI (2.28–12.24); p = 0.0001) were independent prognostic factors for gastric cancer and may serve as a valuable biomarker for the diagnosis and progression of GC and can be helpful in developing individualized treatment strategies for treating GC.     

CCNB1 is a prognostic biomarker for ER+ breast cancer

Identification of effective prognostic biomarkers and targets are of crucial importance to the management of breast cancer. CCNB1 (also known as CyclinB1) belongs to the highly conserved cyclin family and is significantly overexpressed in various cancer types. In this study, we demonstrated that CCNB1 had significant predictive power in distant metastasis free survival, disease free survival, recurrence free survival and overall survival of ER+ breast cancer patients. We also found that CCNB1 was closely associated with hormone therapy resistance. In addition, gene set enrichment analysis (GSEA) revealed that its expression was positively associated with genes overexpressed in endocrine therapy resistant samples. Finally, using CCNB1-Drug interaction network, we demonstrated the interactions between CCNB1 and several available cancer drugs. Overall, we suggest that CCNB1 is a biomarker for the prognosis of ER+ breast cancer and monitoring of hormone therapy efficacy. It is also a promising target for developing new strategies to prevent or even reverse hormone therapy resistance. Moreover, CCNB1 expression may help to monitor hormone therapy and to direct personalized therapies. Nevertheless, in vivo and in vitro experiments and multi-center randomized controlled clinical trials are still needed before its application in clinical settings.     

Serum TIMP-1 in gastric cancer patients: a potential prognostic biomarker

Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) is over-expressed in many human malignancies, including gastric cancer, and is associated with poor outcome. The purpose of this study was to evaluate the clinical and prognostic significance of preoperative serum TIMP-1 levels in gastric cancer patients. One hundred and seventy gastric cancer patients who underwent gastrectomy between 1996 and 2001 were enrolled in this study. The serum concentration of TIMP-1 protein in these patients and in 116 healthy controls was determined using an enzyme-linked immunoassay (ELISA). When a serum TIMP-1 level >95 percentile of healthy controls was set as the upper cut-off value (348.8 ng/ml), abnormally high serum TIMP-1 were observed in 29 (17.1%) of the gastric cancer patients vs 4.3% of healthy controls (p<0.001). The sensitivity and specificity of serum TIMP-1 as a diagnostic tumor marker were 17.1% and 97.7%, respectively. Serum TIMP-1 was positively associated with morphologic appearance (Borrmann type), tumor size, depth of wall invasion, lymph node metastasis, liver metastasis, and peritoneal seeding. It was also positively associated with lymphatic invasion, perineural invasion, and pathological stage. It was not significantly associated with age, gender, tumor location, or histological type. A higher serum TIMP-1 group was significantly associated with lower survival rates than the lower serum TIMP-1 group (cut-off value at the median; 5-yr survival rate: 32.3% vs 55.6%, log-rank p = 0.0011). When the patients were divided into 2 groups using the 95 percentile TIMP-1 level of controls as the cut-off value, 5-yr survival rates were 24.6% and 47.5% respectively for the higher and lower TIMP-1 groups (log rank p = 0.0147). An elevated preoperative level of serum TIMP-1 was significantly associated with progressive disease, advanced stage, and worse survival in gastric cancer patients. Although it is not a good marker for diagnosis, elevated serum TIMP-1 level shows promise as a marker for prognosis in patients with gastric cancer.     

Serum cytokeratin 18 as a biomarker for gastric cancer

Cytokeratin 18 (CK18) fragments are released into circulation during epithelial cell death. M30 (reflects caspase-cleaved CK18 fragment) and M65 (reflects total CK18 fragment) enzyme-linked immunosorbent assay (ELISA) detect circulating CK18 fragments released during caspase-dependent or total cell death, respectively; thus, CK18 has the potential of being a biomarker for epithelial cancers. In the present study, we investigated the serum levels of M30 and M65 in patients with gastric cancer, determined correlation of these levels with clinical features, and evaluated the usefulness of these enzymes as diagnostic and prognostic markers. We enrolled 54 gastric cancer patients and 12 healthy volunteers in this study. We measured the serum levels of M30 and M65 by quantitative ELISA. The levels of M30 and M65 in gastric cancer patients were significantly higher than those in healthy volunteers (P = 0.001, P < 0.001). The enzyme levels were elevated with the progress of gastric cancer. The sensitivity and specificity of M30 as a diagnostic marker were 67.5 and 90.9 %, respectively, and those of M65 were 70.1 and 90.9 %, respectively. The serum levels of M30 and M65 in patient with early gastric cancer were elevated in 38.1 and 66.7 %, respectively. Further, increased serum level of M65 is an independent indicator of poor prognosis (P = 0.036). The serum levels of M30 and M65 may be useful biomarkers for gastric cancer as diagnostic markers that can reflect the extent of cancer. Moreover, M65 levels can be used as a prognostic indicator.     

Tenascin-W is a better cancer biomarker than tenascin-C for most human solid tumors

ABSTRACT: BACKGROUND: Tenascins are large glycoproteins found in the extracellular matrix of many embryonic and adult tissues. Tenascin-C is a well-studied biomarker known for its high overexpression in the stroma of most solid cancers. Tenascin-W, the least studied member of the family, is highly expressed in the stroma of colon and breast tumors and in gliomas, but not in the corresponding normal tissues. Other solid tumors have not been analyzed. The present study was undertaken to determine whether tenascin-W could serve as a cancer-specific extracellular matrix protein in a broad range of solid tumors. METHODS: We analyzed the expression of tenascin-W and tenascin-C by immunoblotting and by immunohistochemistry on multiple frozen tissue microarrays of carcinomas of the pancreas, kidney and lung as well as melanomas and compared them to healthy tissues. RESULTS: From all healthy adult organs tested, only liver and spleen showed detectable levels of tenascin-W, suggesting that tenascin-W is absent from most human adult organs under normal, non-pathological conditions. In contrast, tenascin-W was detectable in the majority of melanomas and their metastases, as well as in pancreas, kidney, and lung carcinomas. Comparing lung tumor samples and matching control tissues for each patient revealed a clear overexpression of tenascin-W in tumor tissues. Although the number of samples examined is too small to draw statistically significant conclusions, there seems to be a tendency for increased tenascin-W expression in higher grade tumors. Interestingly, in most tumor types, tenascin-W is also expressed in close proximity to blood vessels, as shown by CD31 co-staining of the samples. CONCLUSIONS: The present study extends the tumor biomarker potential of tenascin-W to a broad range of solid tumors and shows its accessibility from the blood stream for potential therapeutic strategies.     

Inorganic pyrophosphatase (PPA1) is a negative prognostic marker for human gastric cancer

Inorganic pyrophosphatase (PPA1) is an enzyme which has been found to be upregulated in various tumors, yet its profile in gastrointestinal cancers has not systemically investigated. In present study, gastrointestinal tissue microarrays were used to evaluate PPA1 expression and the association of PPA1 expression with clinical outcomes was determined for patients with gastric cancer by immunohistochemistry. Overexpression of PPA1 was observed in cancers of the esophagus, stomach, and pancreaticobiliary system. PPA1 was overexpressed in 143 cases (51.3%) of the 279 primary gastric tumors and was associated with larger size (> 3 cm), nodal metastasis and advanced clinical staging (P < 0.05). Moreover, survival analysis demonstrated that PPA1 expression was significantly correlated reduced overall of patients with gastric cancer. Therefore, PPA1 may serve as a potential biomarker of poor prognosis in patients with gastric cancer.     

CD44 is a biomarker associated with human prostate cancer radiation sensitivity

CD44 plays an important role in cancer metastasis, chemotherapy, and radiation resistance. The present study investigated the relationship of CD44 expression and radioresistance, and the potential mechanisms of CD44 in radiosensitivity using prostate cancer (CaP) cell lines. CD44 was knocked down in three CaP cell lines (PC-3, PC-3M-luc, and LNCaP) using small interfering RNA (siRNA) and clonogenic survival fractions after single dose irradiation were compared before and after CD44 knocking down (KD). The effect of radiation on cell cycle distribution was examined by flow cytometry and the cell cycle-related protein levels of phospho-Chk1 and phospho-Chk2 were ascertained by Western blotting. The expression of the DNA double strand break (DSB) marker-γH2AX was also quantified by immunofluorescence staining. Our results indicate that the down-regulation of CD44 enhanced radiosensitivity in PC-3, PC-3M-luc, and LNCaP CaP cells, the sensitizing enhancement ratio for these cell lines was 2.3, 1.3, and 1.5, respectively and that the delay of DNA DSB repair in low CD44-expressing KD CaP cells correlated with ineffective cell cycle arrest and the delayed phosphorylation of Chk1 and Chk2. These findings suggest that CD44 may be a valuable biomarker and a predictor of radiosensitivity in CaP treatment.     

Monocarboxylate Transporter 1 (MCT1) is an independent prognostic biomarker in endometrial cancer

Background

Endometrial cancer (EC) is a major health concern due to its rising incidence. Whilst early stage disease is generally cured by surgery, advanced EC has a poor prognosis with limited treatment options. Altered energy metabolism is a hallmark of malignancy. Cancer cells drive tumour growth through aerobic glycolysis and must export lactate to maintain intracellular pH. The aim of this study was to evaluate the expression of the lactate/proton monocarboxylate transporters MCT1 and MCT4 and their chaperone CD147 in EC, with the ultimate aim of directing future drug development.

Methods

MCT1, MCT4 and CD147 expression was examined using immunohistochemical analysis in 90 endometrial tumours and correlated with clinico-pathological characteristics and survival outcomes.

Results

MCT1 and MCT4 expression was observed in the cytoplasm, the plasma membrane or both locations. CD147 was detected in the plasma membrane and associated with MCT1 (p =?0.003) but not with MCT4 (p =?0.207) expression. High MCT1 expression was associated with reduced overall survival (p =?0.029) and remained statistically significant after adjustment for survival covariates (p =?0.017).

Conclusion

Our data suggest that MCT1 expression is an important marker of poor prognosis in EC. MCT1 inhibition may have potential as a treatment for advanced or recurrent EC.

     

Plasma soluble HLA-G is a potential biomarker for diagnosis of colorectal, gastric, esophageal and lung cancer

Human leukocyte antigen-G (HLA-G) is a novel tumor marker and its soluble isoforms produce secretory proteins. Increased soluble HLA-G (sHLA-G) levels have been reported in patients with melanoma, neuroblastoma, lymphoproliferative disorders, breast, ovarian and colorectal carcinoma when compared to healthy controls or subjects with benign neoplasms. The aim of this study is to investigate whether or not plasma sHLA-G can be used as a potential biomarker for cancer diagnosis. We measured plasma sHLA-G levels in 166 patients with early stages of colorectal cancer (CRC, n = 37), gastric cancer (GC, n = 28), esophageal squamous cell carcinoma (ESCC, n = 58) and non-small cell lung cancer (NSCLC, n = 43), and compared them to healthy controls (n = 260) by using a specific HLA-G enzyme-linked immunosorbent assay (ELISA). We found that plasma sHLA-G levels were significantly higher in cancer patients than in healthy controls (all P < 0.0001). The areas under the receiver-operating characteristic (ROC) curves for sHLA-G were 0.97, 0.91, 0.98 and 0.80 for healthy controls vs CRC, GC, ESCC and NSCLC, respectively. At 100% specificity, the highest sensitivity achieved to detect CRC, GC, ESCC and NSCLC was 94% [95% confidence interval (CI), 89-99], 85% (95% CI, 76-94), 91% (95% CI, 88-94) and 51% (95% CI, 43-59) at a cutoff value of 49 U/ml, respectively. These findings suggest that plasma sHLA-G may be a useful molecule in the differential diagnosis of these malignancies against healthy controls.     

ERp57 is a potential biomarker for human fertilization capability

Human infertility is a growing concern and while many assisted reproductive technologies exist, their success rates are low. Thus, developing tests, possibly by assessing proteins involved in fertilization, that could predict the outcome of these technologies is of great significance. To identify candidate proteins, we used two-dimensional polyacrylamide gel electrophoresis and MALDI-TOF techniques and detected the ERp57 protein from human testis protein profile. Immunohistochemistry showed that ERp57 was mostly located in spermatogenic cell cytoplasm from spermatocytes to the spermatozoa phases and in Leydig cells of human testes; it was also present at low levels in Sertoli cells. ERp57 was evident in human spermatozoa, primarily in the acrosome and tail; moreover, it appeared to translocate to the equatorial segment after the acrosome reaction. During sperm capacitation, the ERp57 protein underwent post-translational modification. Blocking ERp57 with antibodies significantly inhibited human sperm from penetrating zona-free hamster oocytes in a dose-dependent manner. Finally, expression levels of ERp57 were associated with fertility; they were decreased dramatically in IVF patients with low fertilization rates compared with those with high rates or to fertile sperm donors. Taken together, these results show that ERp57 is a component of human sperm acrosome proteins, which play a critical role in gamete fusion. Furthermore, ERp57 could be a novel phenotype marker for male infertility and has the potential to be used to assess sperm selection for IVF.     

Caveolin-1 immuno-expression in human gastric cancer: histopathogenetic hypotheses

The immunohistochemical expression of caveolin-1 (cav-1) was evaluated in a series of gastric carcinomas (GC) and in the adjacent normal gastric mucosa. Cav-1 immuno-expression was found in most GC (94%) with a significantly higher amount in the Lauren intestinal type in comparison to the diffuse-type carcinomas. Interestingly, gastric intestinal metaplasia as well as the cells at the base and neck of gastric pits within all fundic mucosal fragments showed an evident cav-1 immuno-staining, suggesting a histogenetic derivation of these lesions from the trans-differentiation of chief cells or from a cryptic progenitor population at the base of fundic glands, as recently hypothesized by other authors. The absence of significant correlations between cav-1 immuno-expression and the other clinico-pathological parameters, such as the stage of disease or the patients overall survival, indicates that the role of cav-1 in GC is neither stage-specific nor related to prognosis.     

Pin1 gene mutation is a rare event in gastric cancer

The peptidyl-prolyl isomerase Pin1 is strikingly overexpressed in human cancers and is a novel regulator of beta-catenin. To determine whether somatic mutation of the Pin1 gene is involved in the development and/or progression of gastric cancer, we searched for mutations of the Pin1 gene in 95 gastric cancer specimens. The effect of Pin1 on beta-catenin expression was further examined in wild- and mutant-type Pin1-transfected HEK 293T cells. We found only one missense mutation that led to the substitution of alanine by aspartic acid at codon 118 of the Pin1 gene. On transfection study, the mutant Pin1 showed an increased expression of beta-catenin. However, the mutation had no effect on expression of the Pin1 protein in the case with Pin1 mutation. These results suggest that Pin1 may not play a role in the development or progression of gastric cancer.