No abstract

BackgroundGlutathione S-transferases (GSTs) are known to abolish or reduce the activities of intracellular enzymes that help detoxify environmental carcinogens, such as those found in tobacco smoke. It has been suggested that polymorphisms in the GST genes are risk factors for lung cancer, but a large number of studies have reported apparently conflicting results. Methods and FindingsLiterature-based meta-analysis was supplemented by tabular data from investigators of all relevant studies of five GST polymorphisms ( GSTM1 null, GSTT1 null, I105V, and A114V polymorphisms in the GSTP1 genes, and GSTM3 intron 6 polymorphism) available before August, 2005, with investigation of potential sources of heterogeneity. Included in the present meta-analysis were 130 studies, involving a total of 23,452 lung cancer cases and 30,397 controls. In a combined analysis, the relative risks for lung cancer of the GSTM1 null and GSTT1 null polymorphisms were 1.18 (95% confidence interval [CI]: 1.14–1.23) and 1.09 (95% CI: 1.02–1.16), respectively, but in the larger studies they were only 1.04 (95% CI: 0.95–1.14) and 0.99 (95% CI: 0.86–1.11), respectively. In addition to size of study, ethnic background was a significant source of heterogeneity among studies of the GSTM1 null genotype, with possibly weaker associations in studies of individuals of European continental ancestry. Combined analyses of studies of the 105V, 114V, and GSTM3*B variants showed no significant overall associations with lung cancer, yielding per-allele relative risks of 1.04 (95% CI: 0.99–1.09), 1.15 (95% CI: 0.95–1.39), and 1.05 (95% CI: 0.89–1.23), respectively. ConclusionsThe risk of lung cancer is not strongly associated with the I105V and A114V polymorphisms in the GSTP1 gene or with GSTM3 intron 6 polymorphism. Given the non-significant associations in the larger studies, the relevance of the weakly positive overall associations with the GSTM1 null and the GSTT1 null polymorphisms is uncertain. As lung cancer has important environmental causes, understanding any genetic contribution to it in general populations will require the conduct of particularly large and comprehensive studies.

The chemokine CXCL12 is highly expressed in gynecologic tumors and is widely known to play a biologically relevant role in tumor growth and spread. Recent evidence suggests that CXCL16, a novel chemokine, is overexpressed in inflammation-associated tumors and mediates pro-tumorigenic effects of inflammation in prostate cancer. We therefore analyzed the expression of CXCL12 and CXCL16 and their respective receptors CXCR4 and CXCR6 in cervical intraepithelial neoplasia (CIN) and cervical cancer and further assessed their association with clinicopathologic features and outcomes. Tissue chip technology and immunohistochemistry were used to analyze the expression of CXCL12, CXCR4, CXCL16, and CXCR6 in healthy cervical tissue (21 cases), CIN (65 cases), and cervical carcinoma (60 cases). The association of protein expression with clinicopathologic features and overall survival was analyzed. These four proteins were clearly detected in membrane and cytoplasm of neoplastic epithelial cells, and their distribution and intensity of expression increased as neoplastic lesions progressed through CIN1, CIN2, and CIN3 to invasive cancer. Furthermore, the expression of CXCR4 was associated significantly with the histologic grade of cervical carcinoma, whereas the expression of CXCR6 was associated significantly with lymph node metastasis. In Kaplan-Meier analysis, patients with high CXCR6 expression had significantly shorter overall survival than did those with low CXCR6 expression. The elevated co-expression levels of CXCL12/CXCR4 and CXCL16/CXCR6 in CIN and cervical carcinoma suggest a durative process in cervical carcinoma development. Moreover, CXCR6 may be useful as a biomarker and a valuable prognostic factor for cervical cancer.

Inter-individual differences in susceptibility to breast cancer are partially mediated through the levels of endogenous and exogenous steroid hormones. The CYP17 gene encodes P450c17alpha, an enzyme that is involved in the metabolism of steroid hormones. Increased endogenous steroid hormone levels have been associated with a MspA1 polymorphism in the 5'-promoter region of the CYP17 gene. The CYP17 MspA1 polymorphism has been postulated as being associated with the risk of developing breast cancer. However, the association between the CYP17 MspA1 polymorphism and breast cancer risk has been controversial in the literature. To re-examine this controversy, we have undertaken a meta-analysis of 15 case-control studies, which included a total of 4227 breast cancer cases and 4730 individual controls. The odds ratio (OR) was used to evaluate the risk of breast cancer for each study, using homozygosity of the wild-type allele as the control group. Statistical analysis showed no evidence of heterogeneity within the studies. The pooled ORs of breast cancer associated with the combined variant (A1/A2 + A2/A2) and the homozygous genotype (A2/A2) were 0.98 (95% CI 0.89-1.07) and 1.05 (95% CI 0.87-1.21), respectively. Similarly, the pooled ORs of advanced breast cancer associated with the combined variant and the homozygous genotype were 0.96 (95% CI 0.77-1.20) and 0.88 (95% CI 0.55-1.41), respectively. A pooling of the studies was also conducted for the various ethnic groups, but failed to show an association of CYP17 MspA1 polymorphism with breast cancer risk in the different ethnic groups. In addition, our results show that a possible protective effect for breast cancer risk of a later age at menarche was mainly limited to women with the A1 homozygous genotype. The OR for age at menarche (> or = 13) was 0.87 (95% CI 0.62-1.17). Our results suggest that CYP17 MspA1 polymorphism may be at best a weak modifier of breast cancer risk but is not a significant independent risk factor.

Degeneration of normal hematopoietic cells is a shared feature of malignant diseases in the hematopoietic system. Previous studies have shown the exhaustion of hematopoietic progenitor cells (HPCs) in leukemic marrow, whereas hematopoietic stem cells (HSCs) remain functional upon relocation to non-leukemic marrow. However, the underlying cellular mechanisms, especially the specific niche components that are responsible for the degeneration of HPCs, are unknown. In this study, we focused on murine bone mesenchymal stem cells (MSCs) and their supporting function for normal hematopoietic cells in Notch1-induced acute T-cell lymphocytic leukemia (T-ALL) mice. We demonstrate that the proliferative capability and differentiation potential of T-ALL MSCs were impaired due to accelerated cellular senescence. RNA-seq analysis revealed significant transcriptional alterations in leukemic MSCs. After co-cultured with the MSCs from T-ALL mice, a specific inhibitory effect on HPCs was defined, whereas in vivo repopulating potential of normal HSCs was not compromised. Furthermore, osteoprotegerin was identified as a cytokine to improve the function of T-ALL MSCs and to enhance normal HPC output via the p38/ERK pathway. Therefore, this study reveals a novel cellular mechanism underlying the inhibition of HPC generation in T-ALL. Leukemic MSCs may serve as a cellular target for improving normal hematopoietic regeneration therapeutically.

No abstract

No abstract

This study is to investigate the anatomical features of maxillae in unilateral cleft lip and palate (UCLP) patients with maxillary retrusion. Additionally, the dissimilarities of retruded maxillae between the UCLP patients and the skeletal class III patients were compared. Craniofacial measurements were carried out among 32 UCLP adult patients with maxillary retrusion (GC), 24 adult patients in class III (SNA < 80°, ANB < 0°) patients (GIII), and 32 normal controls (GN). The authors measured the width and length of the maxillae, as well as their relative positions to the coronal plane passing through basion. The independent sample group t test was performed, and P < 0.05 was regarded as statistically significant. In the GC group, the anterior and posterior maxillary length (A1-P3M⊥CP and P3M-P6M⊥CP) and overall maxillary length (A1-P6M⊥CP) at the dental level, the interdental widths of the maxillae, the maxillary volume (GM), and the volume consisting of maxilla and maxillary sinus (GT) significantly reduced compared with the GN group (P < 0.05). The distances from the points on the maxillae to the coronal plane (A1⊥CP, P3M⊥CP, and P6M⊥CP) in the GC and GIII groups were smaller than those in the GN group (P < 0.05). In summary, for the UCLP patients, the decreased prominence of maxillary complex could be mainly caused by the shortened maxillary length; meanwhile, posterior position of the maxillary body may have some influence on the maxillary protrusion. While for the class III patients, maxillary retrusion was resulted from malposition and malmorphology on an equal basis.