The association of phosphatase and tensin homolog deleted on chromosome 10 polymorphisms and lifestyle habits with colorectal cancer risk in a Chinese population

The biological functions and related signaling pathways of SPON2

Spondin-2 (SPON2), also referred to as M-spondin or DIL-1, is a member of the extracellular matrix protein family known as Mindin-F-spondin (FS). SPON2 can be used as a broad-spectrum tumor marker for more than a dozen tumors, mainly prostate cancer. Meanwhile, SPON2 is also a potential biomarker for the diagnosis of certain non-tumor diseases. Additionally, SPON2 plays a pivotal role in regulating tumor metastasis and progression. In normal tissues, SPON2 has a variety of biological functions represented by promoting growth and development and cell proliferation. This paper presents a comprehensive overview of the regulatory mechanisms, diagnostic potential as a broad-spectrum biomarker, diverse biological functions, involvement in various signaling pathways, and clinical applications of SPON2.

The PI3K/Akt/mTOR axis in colorectal cancer: Oncogenic alterations, non-coding RNAs, therapeutic opportunities, and the emerging role of nanoparticles

Colorectal cancer (CRC) is one of the deadliest human malignancies worldwide. Several molecular pathways have been demonstrated to be involved in the initiation and development of CRC which among them, the overactivation of the phosphatidyl-inositol 3-kinase (PI3K)/Akt/mTOR axis is of importance. The current review aims to unravel the mechanisms by which the PI3K/Akt/mTOR pathway affects CRC progression; and also, to summarize the original data obtained from international research laboratories on the oncogenic alterations and polymorphisms affecting this pathway in CRC. Besides, we provide a special focus on the regulatory role of noncoding RNAs targeting the PI3K/Akt/mTOR pathway in this malignancy. Questions on how this axis is involved in the inhibition of apoptosis, in the induction of drug resistance, and the angiogenesis, epithelial to mesenchymal transition, and metastasis are also responded. We also discussed the PI3K/Akt pathway-associated prognostic and predictive biomarkers in CRC. In addition, we provide a general overview of PI3K/Akt/mTOR pathway inhibition whether by chemical-based drugs or by natural-based medications in the context of CRC, either as monotherapy or in combination with other therapeutic agents; however, those treatments might have life-threatening side effects and toxicities. To the best of our knowledge, the current review is one of the first ones highlighting the emerging roles of nanotechnology to overcome challenges related to CRC therapy in the hope that providing a promising platform for the treatment of CRC.

Mindin serves as a tumour suppressor gene during colon cancer progression through MAPK/ERK signalling pathway in mice

Mindin is important in broad spectrum of immune responses. On the other hand, we previously reported that mindin attenuated human colon cancer development by blocking angiogenesis through Egr-1-mediated regulation. However, the mice original mindin directly suppressed the syngenic colorectal cancer (CRC) growth in our recent study and we aimed to further define the role of mindin during CRC development in mice. We established the mouse syngeneic CRC CMT93 and CT26 WT cell lines with stable mindin knock-down or overexpression. These cells were also subcutaneously injected into C57BL/6 and BALB/c mice as well as established a colitis-associated colorectal cancer (CAC) mouse model treated with lentiviral-based overexpression and knocked-down of mindin. Furthermore, we generated mindin knockout mice using a CRISPR-Cas9 system with CAC model. Our data showed that overexpression of mindin suppressed cell proliferation in both of CMT93 and CT26 WT colon cancer cell lines, while the silencing of mindin promoted in vitro cell proliferation via the ERK and c-Fos pathways and cell cycle control. Moreover, the overexpression of mindin significantly suppressed in vivo tumour growth in both the subcutaneous transplantation and the AOM/DSS-induced CAC models. Consistently, the silencing of mindin reversed these in vivo observations. Expectedly, the tumour growth was promoted in the CAC model on mindin-deficient mice. Thus, mindin plays a direct tumour suppressive function during colon cancer progression and suggesting that mindin might be exploited as a therapeutic target for CRC.

Association of genetic variations in phosphatase and tensin homolog (PTEN) gene with polycystic ovary syndrome in South Indian women: a case control study

PURPOSE

The purpose of the study was to investigate the association between gene phosphate and tensin homolog (PTEN) single nucleotide polymorphisms (SNPs) and risk of developing polycystic ovary syndrome (PCOS) in South Indian women. PTEN is one of the most important tumor suppressor genes that regulate cell proliferation, migration, and death. It is also involved in the maintenance of genome stability. PCOS is one of the most common endocrine disorders among women of reproductive age. It is a heterogeneous syndrome characterized by abnormal reproductive cycles, irregular ovulation, hormonal imbalance, hyperandrogenism, acne and hirsutism.

RESEARCH QUESTION

What is the association status of PTEN SNPs with PCOS?

METHODS

A total of 240 subjects were recruited in this case-control study comprising 110 patients with PCOS and 130 individuals without PCOS. All the subjects were of South Indian origin. The genotyping of PTEN SNPs (rs1903858 A/G, rs185262832G/A and rs10490920T/C) was carried out on DNA from subjects by polymerase chain reaction (PCR) and sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pairwise linkage disequilibrium (LD) were surveyed by Haploview Software.

RESULTS

Our results showed significant increase in the frequencies of rs1903858 A/G (P = 0.0016), rs185262832 G/A (P = 0.0122) and rs10490920 T/C (P = 0.0234) genotypes and alleles in cases compared to controls.

CONCLUSION

The PTEN (rs1903858A/G, rs185262832G/A and rs10490920T/C) gene polymorphisms may constitute an inheritable risk factor for PCOS in South Indian women.

XRCC2 Polymorphisms and Environmental Factors Predict High Risk of Colorectal Cancer

Background

This case-control study aimed to analyze the association of XRCC2 polymorphisms (rs3218408 and rs3218384) with colorectal cancer (CRC) risk. The interaction of XRCC2 polymorphisms with environmental factors was investigated as well.

Material/Methods

We enrolled 147 CRC patients and 114 healthy individuals into the study. Polymerase chain reaction (PCR)-sequencing method was performed to detect rs3218408 and rs3218384 polymorphisms. Hardy-Weinberg equilibrium (HWE) was checked in the control group. Odds ratio (OR) with 95% confidence interval (CI) represented the risk of CRC. Cross-table method was used in analyzing the interaction effects.

Results

Compared to the control group, the frequency of smokers was much higher in the case group (P<0.001). A similar result was observed in drinkers (55.8% vs. 40.4%, P=0.013). Dietary habits of all subjects were investigated as well, showing that CRC patients ate fewer vegetables than did healthy controls (P<0.001). In the analysis of polymorphisms, rs3218408 appeared to be an independent risk factor of CRC (GG: OR=2.048, 95%CI=1.032–4.061; G allele: OR=1.445, 95%CI=1.019–2.049). There were 68 (76.4%) C allele carriers (rs3218384) among smokers, which was higher than the number of G allele carriers (P<0.001). A similar outcome was observed for alcohol drinkers (P=0.048), which suggests a relationship of rs3218384 with smoking and drinking. Further analysis indicated that interaction of rs3218384 with smoking increased the risk of CRC (GG and smoking: OR=3.250, 95%CI=1.235–8.556; GC+CC and smoking: OR=2.167, 95%CI=1.175–3.996).

Conclusions

We found that rs3218408 was related with increased risk of CRC, and the interaction of rs3218384 with smoking increased the risk of CRC.

Single nucleotide polymorphisms rs701848 and rs2735343 in PTEN increases cancer risks in an Asian population

We performed this meta-analysis to analyze the cancer risk to individuals carrying the rs701848 and rs2735343 single nucleotide polymorphisms (SNPs) in the phosphatase and tensin homolog (PTEN) gene. We searched the PubMed, EMBASE, Cochrane library and the national knowledge infrastructure of China (CNKI) databases and identified 18 eligible case-control studies with 5458 cases and 6003 controls for rs701848 as well as 5490 cases and 6209 controls for rs2735343. Our analyses demonstrated that cancer risk was associated with rs701848 in the recessive model (CC vs. CT+TT, OR=1.169, 95% CI: 1.061-1.288) and with rs2735343 in the dominant model (GC+CC vs. GG, OR=0.758, 95% CI: 0.590-0.972). Subgroup analysis showed that in Asian subjects, carrying the C allele of rs701848 or GG genotype of rs2735343 was associated with increased cancer risk. Moreover, Asian subjects carrying the TC/CC genotype or C allele of rs701848 were associated with increased risk of esophageal squamous cell cancer. This meta-analysis indicates that the PTEN rs701848 (CC) and rs2735343 (GG) polymorphisms are associated with increased cancer risk in Asian subjects.

The extracellular matrix protein mindin attenuates colon cancer progression by blocking angiogenesis via Egr-1-mediated regulation

Mindin, a secreted, highly conserved extracellular matrix (ECM) protein, exerts a broad spectrum of effects on the innate immune system. However, its function in colorectal cancer (CRC) progression is not well established, and its upstream regulation mechanisms remain unclear. Contrary to previous reports, this study used two different enzyme-linked immunosorbent assay (ELISA) kits to show that the serum level of mindin was significantly decreased in CRC patients and that this decreased level is more significantly associated with the early stages of the disease. To explore the regulation of mindin, we used a bioinformatics approach to predict potential transcription factors and determined that early growth response factor (Egr)-1 directly regulates mindin expression at the transcriptional level using dual luciferase, chromatin immunoprecipitation (ChIP) DNA and electrophoretic mobility shift assay (EMSA) methods. Egr-1 regulates mindin mRNA and protein expression in CRC cells, and the protein expression of both Egr-1 and mindin was significantly decreased in tumor lesions of patients compared with adjacent control tissues. Mindin is essential for Egr-1-mediated inhibition of endothelial cell tube formation, and mindin inhibits endotheliocyte proliferation, migration and angiogenic sprouts in vitro. Overexpression of mindin suppressed xenograft tumor growth by blocking angiogenesis instead of directly suppressing CRC cell proliferation. Mechanically, mindin inhibits the hypoxia-induced HIF-1a and VEGFA protein expression in CRC cells and the phosphorylation of VEGFR-2 in endothelial cells. The results suggest that the serum level of mindin can be used as a novel biomarker for early detection of CRC and that the Egr-1/mindin axis is a potential therapeutic target for the inhibition of angiogenesis in CRC development.

PTEN polymorphisms contribute to clinical outcomes of advanced lung adenocarcinoma patients treated with platinum-based chemotherapy

This study aimed to elucidate the impact of PTEN single nucleotide polymorphism (SNP) on clinical outcomes for advanced lung adenocarcinoma (LAC) patients treated with platinum-based chemotherapy. Three functional SNPs (rs11202607 G>A, rs701848 A>G, and rs11202592 G>C) of PTEN gene were genotyped by using DNA from blood samples of 618 advanced LAC patients, and their relationships with clinical outcomes were analyzed. The carriers of homozygous mutant of rs701848 and rs11202592 polymorphisms revealed significantly worse overall survival (OS) than those with heterozygote or wild-type homozygote (18.83 vs. 21.47 vs. 24.37 months, P = 0.034 and 13.40 vs. 19.03 vs. 21.90 months, P = 0.025, respectively). Subgroup analysis revealed that this association was particularly significant in tumor-lymph-node metastasis (TNM) stage III patients. The objective response rates (ORR) and disease control rates (DCR) of patients with genotype AA, AG, and GG in PTEN rs701848 polymorphism were statistically different (24.1 vs 16.6 vs 12.2 %, P = 0.017 and 82.7 vs 76.0 vs 70.2 %, P = 0.029, respectively). Haplotype analysis revealed a protective effect of the haplotype G-A-A (in the order of rs11202592, rs701848, and rs11202607) on chemotherapy efficacy and survival. Taken together, PTEN polymorphisms may contribute to survival and chemotherapy efficacy of advanced LAC patients treated with platinum-based agents.

Genetic variants in the inositol phosphate metabolism pathway and risk of different types of cancer

Members of the inositol phosphate metabolism pathway regulate cell proliferation, migration and phosphatidylinositol-3-kinase (PI3K)/Akt signaling, and are frequently dysregulated in cancer. Whether germline genetic variants in inositol phosphate metabolism pathway are associated with cancer risk remains to be clarified. We examined the association between inositol phosphate metabolism pathway genes and risk of eight types of cancer using data from genome-wide association studies. Logistic regression models were applied to evaluate SNP-level associations. Gene- and pathway-based associations were tested using the permutation-based adaptive rank-truncated product method. The overall inositol phosphate metabolism pathway was significantly associated with risk of lung cancer (P = 2.00 × 10⁻⁴), esophageal squamous cell carcinoma (P = 5.70 × 10⁻³), gastric cancer (P = 3.03 × 10⁻²) and renal cell carcinoma (P = 1.26 × 10⁻²), but not with pancreatic cancer (P = 1.40 × 10⁻¹), breast cancer (P = 3.03 × 10⁻¹), prostate cancer (P = 4.51 × 10⁻¹), and bladder cancer (P = 6.30 × 10⁻¹). Our results provide a link between inherited variation in the overall inositol phosphate metabolism pathway and several individual genes and cancer. Further studies will be needed to validate these positive findings, and to explore its mechanisms.