Programmed cell death 6 (PDCD6) as a prognostic marker for gastric cancers

Association between PDCD6-VNTR polymorphism and urinary cancer susceptibility

BACKGROUND

Programmed cell death 6 (PDCD6) is known to be involved in apoptosis and tumorigenesis. Given the reported association with urinary cancer susceptibility through SNP analysis, we further analyzed the entire genomic structure of PDCD6.

METHODS

Three VNTR regions (MS1-MS3) were identified through the analysis of the genomic structure of PDCD6. To investigate the association between these VNTR regions and urinary cancer susceptibility, genomic DNA was extracted from 413 cancer-free male controls, 267 bladder cancer patients, and 331 prostate cancer patients. Polymerase chain reaction (PCR) was performed to analyze the PDCD6-MS regions. Statistical analysis was performed to determine the association between specific genotypes and cancer risk. In addition, the effect of specific VNTRs on PDCD6 expression was also confirmed using a reporter vector.

RESULTS

Among the three VNTR regions, MS1 and MS2 exhibited monomorphism, while the MS3 region represented polymorphism, with its transmission to subsequent generations through meiosis substantiating its utility as a DNA typing marker. In a case-control study, the presence of rare alleles within PDCD6-MS3 exhibited significant associations with both bladder cancer (OR = 2.37, 95% CI: 1.33-4.95, P = 0.019) and prostate cancer (OR = 2.11, 95% CI: 1.03-4.36, P = 0.038). Furthermore, through luciferase assays, we validated the impact of the MS3 region on modulating PDCD6 expression.

CONCLUSIONS

This study suggests that the PDCD6-MS3 region could serve as a prognostic marker for urinary cancers, specifically bladder cancer and prostate cancer. Moreover, the subdued influence exerted by PDCD6-MS3 on the expression of PDCD6 offers another insight concerning the progression of urinary cancer.

Multifaceted roles of PDCD6 both within and outside the cell

Programmed cell death protein 6 (PDCD6) is an evolutionarily conserved Ca2+-binding protein. PDCD6 is involved in regulating multifaceted and pleiotropic cellular processes in different cellular compartments. For instance, nuclear PDCD6 regulates apoptosis and alternative splicing. PDCD6 is required for coat protein complex II-dependent endoplasmic reticulum-to-Golgi apparatus vesicular transport in the cytoplasm. Recent advances suggest that cytoplasmic PDCD6 is involved in the regulation of cytoskeletal dynamics and innate immune responses. Additionally, membranous PDCD6 participates in membrane repair through endosomal sorting complex required for transport complex-dependent membrane budding. Interestingly, extracellular vesicles are rich in PDCD6. Moreover, abnormal expression of PDCD6 is closely associated with many diseases, especially cancer. PDCD6 is therefore a multifaceted but pivotal protein in vivo. To gain a more comprehensive understanding of PDCD6 functions and to focus and stimulate PDCD6 research, this review summarizes key developments in its role in different subcellular compartments, processes, and pathologies.

Identification of Key Genes Related to Immune Cells in Patients with COVID-19 Via Integrated Bioinformatics-Based Analysis

COVID-19 has spread all over the world which poses a serious threat to social economic development and public health. Despite enormous progress has been made in the prevention and treatment of COVID-19, the specific mechanism and biomarker related to disease severity or prognosis have not been clarified yet. Our study intended to further explore the diagnostic markers of COVID-19 and their relationship with serum immunology by bioinformatics analysis. The datasets about COVID-19 were downloaded from the Gene Expression Omnibus (GEO) dataset. The differentially expressed genes (DEGs) were selected via the limma package. Then, weighted gene co-expression network analysis (WGCNA) was conducted to identify the critical module associated with the clinic status. The intersection DEGs were processed for further enrichment analysis. The final diagnostic genes for COVID-19 were selected and verified through special bioinformatics algorithms. There were significant DEGs between the normal and COVID-19 patients. These genes were mainly enriched in cell cycle, complement and coagulation cascade, extracellular matrix (ECM) receptor interaction, and the P53 signaling pathway. As much as 357 common intersected DEGs were selected in the end. These DEGs were enriched in organelle fission, mitotic cell cycle phase transition, DNA helicase activity, cell cycle, cellular senescence, and P53 signaling pathway. Our study also identified CDC25A, PDCD6, and YWAHE were potential diagnostic markers of COVID-19 with the AUC (area under curve), 0.958 (95% CI 0.920-0.988), 0.941(95% CI 0.892-0.980), and 0.929 (95% CI 0.880-0.971). Moreover, CDC25A, PDCD6, and YWAHE were correlated with plasma cells, macrophages M0, T cells CD4 memory resting, T cells CD8, dendritic cells, and NK cells. Our study discovered that CDC25A, PDCD6, and YWAHE can be used as diagnostic markers for COVID-19. Moreover, these biomarkers were also closely associated with immune cell infiltration, which plays a pivotal role in the diagnosis and progression of COVID-19.

Electroacupuncture-Regulated miR-34a-3p/PDCD6 Axis Promotes Post-Spinal Cord Injury Recovery in Both In Vitro and In Vivo Settings

Electroacupuncture (EA) could enhance neuroregeneration and posttraumatic conditions; however, the underlying regulatory mechanisms remain ambiguous. PDCD6 (programmed cell death 6) is an established proapoptotic regulator which is responsible for motoneuronal death. However, its potential regulatory role in post-spinal cord injury (SCI) regeneration has remained largely unknown. Further investigations are warranted to clarify the involvement of PDCD6 post-SCI recovery and the underlying mechanisms. In our study, based on bioinformatics prediction, we found that miR-34a-3p might be an upstream regulator miRNA for PDCD6, which was subsequently validated through combined utilization of the qRT-PCR, western blot, and dual-luciferase reporter system. Our in vitro results showed that miR-34a-3p might promote the in vitro differentiation of neural stem cell (NSC) through suppressing PDCD6 and regulating other important neural markers such as fibroblast growth factor receptor 1 (FGFR1), MAP1/2 (MAP kinase kinases 1/2), myelin basic protein (MBP), βIII-tubulin Class III β-tubulin (βIII tubulin), and glial fibrillary acidic protein (GFAP). Notably, in the post-SCI rat model, exogenous miR-34a-3p agomir obviously inhibited the expression of PDCD6 at the protein level and promoted neuronal proliferation, motoneurons regeneration, and axonal myelination. The restorations at cellular level might contribute to the improved hindlimbs functions of post-SCI rats, which was manifested by the Basso-Beattie-Bresnahan (BBB) locomotor test. The impact of miR-34a-3p was further promoted by EA treatment in vivo. Conclusively, this paper argues that a miR-34a-3p/PDCD6 axis might be a candidate therapeutic target for treating SCI and that the therapeutic effect of EA is driven through this pathway.

Proteomic profiling of milk small extracellular vesicles from bovine leukemia virus-infected cattle

Milk small extracellular vesicles (sEV) contain proteins that provide potential information of host physiology and immunology. Bovine leukemia virus (BLV) is an oncogenic virus that causes progressive B-cell lymphosarcoma in cattle. In this study, we aimed to explore the proteomic profile of milk sEV from BLV-infected cattle compared with those from uninfected cattle. Milk sEV were isolated from three BLV-infected and three uninfected cattle. Proteomic analysis was performed by using a comprehensive nanoLC-MS/MS method. Furthermore, gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to evaluate the candidates for uniquely or differentially expressed proteins in milk sEV from BLV-infected cattle. Proteomic analysis revealed a total of 1330 common proteins in milk sEV among BLV-infected cattle, whereas 118 proteins were uniquely expressed compared with those from uninfected cattle. Twenty-six proteins in milk sEV were differentially expressed proteins more than two-fold significant difference (p < 0.05) in BLV-infected cattle. GO and KEGG analyses indicated that the candidates for uniquely or differentially expressed proteins in milk sEV had been involved in diverse biological activities including metabolic processes, cellular processes, respond to stimulus, binding, catalytic activities, cancer pathways, focal adhesion, and so on. Taken together, the present findings provided a novel insight into the proteomes of milk sEV from BLV-infected cattle.

The Novel ALG-2 Target Protein CDIP1 Promotes Cell Death by Interacting with ESCRT-I and VAPA/B

Apoptosis-linked gene 2 (ALG-2, also known as PDCD6) is a member of the penta-EF-hand (PEF) family of Ca²⁺-binding proteins. The murine gene encoding ALG-2 was originally reported to be an essential gene for apoptosis. However, the role of ALG-2 in cell death pathways has remained elusive. In the present study, we found that cell death-inducing p53 target protein 1 (CDIP1), a pro-apoptotic protein, interacts with ALG-2 in a Ca²⁺-dependent manner. Co-immunoprecipitation analysis of GFP-fused CDIP1 (GFP-CDIP1) revealed that GFP-CDIP1 associates with tumor susceptibility gene 101 (TSG101), a known target of ALG-2 and a subunit of endosomal sorting complex required for transport-I (ESCRT-I). ESCRT-I is a heterotetrameric complex composed of TSG101, VPS28, VPS37 and MVB12/UBAP1. Of diverse ESCRT-I species originating from four VPS37 isoforms (A, B, C, and D), CDIP1 preferentially associates with ESCRT-I containing VPS37B or VPS37C in part through the adaptor function of ALG-2. Overexpression of GFP-CDIP1 in HEK293 cells caused caspase-3/7-mediated cell death. In addition, the cell death was enhanced by co-expression of ALG-2 and ESCRT-I, indicating that ALG-2 likely promotes CDIP1-induced cell death by promoting the association between CDIP1 and ESCRT-I. We also found that CDIP1 binds to vesicle-associated membrane protein-associated protein (VAP)A and VAPB through the two phenylalanines in an acidic tract (FFAT)-like motif in the C-terminal region of CDIP1, mutations of which resulted in reduction of CDIP1-induced cell death. Therefore, our findings suggest that different expression levels of ALG-2, ESCRT-I subunits, VAPA and VAPB may have an impact on sensitivity of anticancer drugs associated with CDIP1 expression.

Natural compound catechol induces DNA damage, apoptosis, and G1 cell cycle arrest in breast cancer cells

Targeting cell cycle and inducing DNA damage by activating cell death pathways are considered as effective therapeutic strategy for combating breast cancer progression. Many of the naturally known small molecules target these signaling pathways and are effective against resistant and/or aggressive types of breast cancers. Here, we investigated the effect of catechol, a naturally occurring plant compound, for its specificity and chemotherapeutic efficacies in breast cancer (MCF-7 and MDA-MB-231) cells. Catechol treatment showed concentration-dependent cytotoxicity and antiproliferative growth in both MCF-7 and MDA-MB-231 cells while sparing minimal effects on noncancerous (F-180 and HK2) cells. Catechol modulated differential DNA damage effects by activating ATM/ATR pathways and showed enhanced γ-H2AX expression, as an indicator for DNA double-stranded breaks. MCF-7 cells showed G1 cell cycle arrest by regulating p21-mediated cyclin E/Cdk2 inhibition. Furthermore, activation of p53 triggered a caspase-mediated cell death mechanism by inhibiting regulatory proteins such as DNMT1, p-BRCA1, MCL-1, and PDCD6 with an increased Bax/Bcl-2 ratio. Overall, our results showed that catechol possesses favorable safety profile for noncancerous cells while specifically targeting multiple signaling cascades to inhibit proliferation in breast cancer cells.

miR-9875 functions in antiviral immunity by targeting PDCD6 in mud crab (Scylla paramamosain)

Programmed cell death 6 (PDCD6) is a well-known apoptosis regulator that is involved in the immunity of mammals. However, the effects of miRNA-mediated regulation of PDCD6 expression on apoptosis and virus infection in organisms, especially in marine invertebrates, have not been extensively explored. In this study, PDCD6 of mud crab (Scylla paramamosain) (Sp-PDCD6) was characterized. The results showed that Sp-PDCD6 contains five EF-hands domains and could suppress virus infection via apoptosis promotion. It also presented that Sp-PDCD6 was directly targeted by miR-9875 in vitro and in vivo, miR-9875 served as a positive regulator during the virus invasion. The findings indicated that the miR-9875-PDCD6 pathway possessed fundamental effects on the immune response to virus infection in mud crab. Therefore, our research provided a novel insight into the roles of both miR-9875 and PDCD6 in the regulation of apoptosis and virus defense in mud crab.

PDCD6 cooperates with C-Raf to facilitate colorectal cancer progression via Raf/MEK/ERK activation

Background

Colorectal cancer (CRC) is one of the most common malignancies, and it’s expected that the CRC burden will substantially increase in the next two decades. New biomarkers for targeted treatment and associated molecular mechanism of tumorigenesis remain to be explored. In this study, we investigated whether PDCD6 plays an oncogenic role in colorectal cancer and its underlying mechanism.

Methods

Programmed cell death protein 6 (PDCD6) expression in CRC samples were analyzed by immunohistochemistry and immunofluorescence. The prognosis between PDCD6 and clinical features were analyzed. The roles of PDCD6 in cellular proliferation and tumor growth were measured by using CCK8, colony formation, and tumor xenograft in nude mice. RNA-sequence (RNA-seq), Mass Spectrum (MS), Co-Immunoprecipitation (Co-IP) and Western blot were utilized to investigate the mechanism of tumor progression. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were performed to determine the correlation of PDCD6 and MAPK pathway.

Results

Higher expression levels of PDCD6 in tumor tissues were associated with a poorer prognosis in patients with CRC. Furthermore, PDCD6 increased cell proliferation in vitro and tumor growth in vivo. Mechanistically, RNA-seq showed that PDCD6 could affect the activation of the MAPK signaling pathway. PDCD6 interacted with c-Raf, resulting in the activation of downstream c-Raf/MEK/ERK pathway and the upregulation of core cell proliferation genes such as MYC and JUN.

Conclusions

These findings reveal the oncogenic effect of PDCD6 in CRC by activating c-Raf/MEK/ERK pathway and indicate that PDCD6 might be a potential prognostic indicator and therapeutic target for patients with colorectal cancer.

Association of PDCD6 polymorphisms with the risk of cancer: Evidence from a meta-analysis

This study was designed to evaluate the relationship between Programmed cell death protein 6 (PDCD6) polymorphisms and cancer susceptibility. The online databases were searched for relevant case-control studies published up to November 2017. Review Manage (RevMan) 5.3 was used to conduct the statistical analysis. The pooled odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the strength of association. Overall, our results indicate that PDCD6 rs3756712 T>G polymorphism was significantly associated with decreased risk of cancer under codominant (OR = 0.82, 95%CI = 0.70-0.96, p = 0.01, TG vs TT; OR = 0.53, 95%CI = 0.39-0.72, p < 0.0001, GG vs TT), dominant (OR = 0.76, 95%CI = 0.66-0.89, p = 0.0004, TG+GG vs TT), recessive (OR = 0.57, 95%CI = 0.43-0.78, p = 0.0003, GG vs TT+TG), and allele (OR = 0.76, 95%CI = 0.67-0.86, p < 0.00001, G vs T) genetic model. The finding did not support an association between rs4957014 T>G polymorphism of PDCD6, and different cancers risk.

Apoptosis-linked gene 2 promotes breast cancer growth and metastasis by regulating the cytoskeleton

Breast cancer is the most prevalent cancer in women. Although it begins as local disease, breast cancer frequently metastasizes to the lymph nodes and distant organs. Therefore, novel therapeutic targets are needed for the management of this disease. Apoptosis-linked gene 2 (ALG-2) is a calcium-binding protein crucial for diverse physiological processes and has recently been implicated in cancer development. However, it remains unclear whether this protein is involved in the pathogenesis of breast cancer. Here, we demonstrate that the expression of ALG-2 is significantly upregulated in breast cancer tissues and is correlated with clinicopathological characteristics indicative of tumor malignancy. Our data further show that ALG-2 stimulates breast cancer growth and metastasis in mice. ALG-2 also promotes breast cancer cell proliferation, survival, and motility in vitro. Mechanistic data reveal that ALG-2 disrupts the localization of centrosome proteins, resulting in spindle multipolarity and chromosome missegregation. In addition, ALG-2 drives the polarization and migration of breast cancer cells by facilitating the rearrangement of microtubules and microfilaments. These findings reveal a critical role for ALG-2 in the pathogenesis of breast cancer and have important implications for its diagnosis and therapy.

ALG2 regulates glioblastoma cell proliferation, migration and tumorigenicity

Apoptosis-linked gene-2 (ALG-2), also known as programmed cell death 6 (PDCD6), has recently been reported to be aberrantly expressed in various tumors and required for tumor cell viability. The aim of the present study was to investigate whether ALG-2 plays a crucial role in tumor cell proliferation, migration and tumorigenicity. In this study, we examined the expression of PDCD6 in glioblastoma cell lines and found that ALG-2 was generally expressed in glioblastoma cell lines. We also performed an analysis of an online database and found that high expression of ALG-2 was associated with poor prognosis (p = 0.039). We found that over-expression of ALG2 in glioblastoma could inhibit cell proliferation and, conversely, that down-regulation of ALG2 could promote cell proliferation. Further studies showed that over-expression of ALG2 inhibited the migration of tumor cells, whereas down-regulation of ALG2 promoted tumor cell migration. Finally, in vitro and in vivo studies showed that over-expression of ALG2 inhibited the tumorigenic ability of tumor cells, while down-regulation of ALG2 promoted tumor cell tumorigenic ability. In conclusion, ALG2 has a tumor suppressive role in glioblastoma and might be a potential target for the treatment of glioblastoma.

Deregulated ALG-2/HEBP2 axis alters microtubule dynamics and mitotic spindle behavior to stimulate cancer development

Cancer cells are characterized by genomic instability, resulting in the accumulation of mutations that promote cancer progression. One way that genomic instability can arise is through improper regulation of the microtubule cytoskeleton that impacts the function of the mitotic spindle. In this study, we have identified a critical role for the interaction between apoptosis-linked gene 2 (ALG-2) and heme-binding protein 2 (HEBP2) in the above processes. Our data show that the gene copy numbers and mRNA levels for both ALG-2 and HEBP2 are significantly upregulated in breast and lung cancer. Coexpression of ALG-2 and HEBP2 markedly increases the cytoplasmic pool of ALG-2 and alters the subcellular distribution of HEBP2. Our data further reveal that abnormality in the ALG-2/HEBP2 interaction impairs spindle orientation and positioning during mitosis. In addition, this complex appears to modulate the dynamic properties of microtubules in cancer cells. These finding thus uncover an important function for deregulated ALG-2/HEBP2 axis in cancer development by influencing microtubule dynamics and spindle behavior, providing novel insight into the etiology and pathogenesis of cancer.

Screening and Characterization of a Non-cyp51A Mutation in an Aspergillus fumigatus cox10 Strain Conferring Azole Resistance

The rapid and global emergence of azole resistance in the human pathogen Aspergillus fumigatus has drawn attention. Thus, a thorough understanding of its mechanisms of drug resistance requires extensive exploration. In this study, we found that the loss of the putative calcium-dependent protein-encoding gene algA causes an increased frequency of azole-resistant A. fumigatus isolates. In contrast to previously identified azole-resistant isolates related to cyp51A mutations, only one isolate carries a point mutation in cyp51A (F219L mutation) among 105 independent stable azole-resistant isolates. Through next-generation sequencing (NGS), we successfully identified a new mutation (R243Q substitution) conferring azole resistance in the putative A. fumigatus farnesyltransferase Cox10 (AfCox10) (AFUB_065450). High-performance liquid chromatography (HPLC) analysis verified that the decreased absorption of itraconazole in related Afcox10 mutants is the primary reason for itraconazole resistance. Moreover, a complementation experiment by reengineering the mutation in a parental wild-type background strain demonstrated that both the F219L and R243Q mutations contribute to itraconazole resistance in an algA-independent manner. These data collectively suggest that the loss of algA results in an increased frequency of azole-resistant isolates with a non-cyp51A mutation. Our findings indicate that there are many unexplored non-cyp51A mutations conferring azole resistance in A. fumigatus and that algA defects make it possible to isolate drug-resistant alleles. In addition, our study suggests that genome-wide sequencing combined with alignment comparison analysis is an efficient approach to identify the contribution of single nucleotide polymorphism (SNP) diversity to drug resistance.

Luteinizing hormone inhibits cisplatin-induced apoptosis in human epithelial ovarian cancer cells

The elevation of Luteinizing hormone (LH) is commonly observed in epithelial ovarian cancer. This correlation suggests a causal relationship between LH and ovarian cancer. LH has been reported to inhibit apoptosis in ovarian cancer cells. Programmed cell death gene 6 (PDCD6), also known as apoptosis-linked gene-2, is an apoptotic mediator that is required for apoptosis to numerous death stimuli. Therefore, the aim of the present study was to determine whether PDCD6 may be induced by LH in ovarian cancer, and whether LH may affect the apoptosis through PDCD6. Flow cytometry was used to detect the effects of cisplatin on the induction of apoptosis by LH. PDCD6 expression was monitored by quantitative polymerase chain reaction and western blotting. The signaling transduction pathways were also investigated by western blotting. The present study demonstrated that LH reduced cisplatin-induced apoptosis in ovarian OVCAR-3 and SKOV-3 cancer cells. The results indicated that PDCD6 expression was inhibited by LH. In addition, the inhibition of PDCD6, induced by LH, was mediated through the activation of the phosphatidylinositol 3-kinase/protein kinase B and p44/42 mitogen-activated protein kinase transduction signaling pathways. The present results suggest that LH affects the sensitivity of ovarian cancer cells to chemotherapy, primarily by signaling to inhibit apoptosis and to additionally suppress PDCD6.

Single nucleotide polymorphisms in PDCD6 gene are associated with the development of cervical squamous cell carcinoma

The programmed cell death 6 (PDCD6), discovered as a proapoptotic calcium-binding protein, has recently been found dysregulated in tumors of various origin and contributed to cancer cell viability. The aim of this study was to determine whether SNPs in PDCD6 are associated with cervical squamous cell carcinoma (CSCC). Polymerase chain reaction-restriction fragment length polymorphism method was used to genotype two tag SNPs (rs3756712 and rs4957014) of PDCD6 in 328 CSCC patients and 541 controls. Significantly increased CSCC risks were found to be associated with T allele of rs3756712 and G allele of rs4957014 (P = 0.017, OR = 1.320, and P = 0.007, OR = 1.321, respectively). CSCC risks were associated with these two SNPs in different genetic model (P = 0.04, OR = 1.78 for rs3756712 in a recessive model, and P = 0.006, OR = 2.01 for rs4957014 in a codominant model, respectively). Results of stratified analyses revealed that rs4957014 is associated with parametrial invasion of CSCC (P = 0.044, OR = 1.414). Our results suggest that these two tag SNPs of PDCD6 are associated with CSCC, indicating that PDCD6 may play an important role in the pathogenesis of CSCC.

Comparative proteomics analysis of global cellular stress responses to hydroxyurea-induced DNA damage in HeLa cells

Both environmental agents and spontaneous cellular events cause serious DNA damage, threatening the integrity of the genome. In response to replication stress or genotoxic agents triggered DNA damage, degradation of p12 subunit of DNA polymerase delta (Pol δ) results in an inter-conversion between heterotetramer (Pol δ4) and heterotrimer (Pol δ3) forms and plays a significant role in DNA damage response in eukaryotic cells. In this work, we used mass spectrometry-based proteomic approach to identify those cellular stress response protein changes corresponding to the degradation of p12 in DNA-damaged HeLa cells by the treatment with hydroxyurea (HU). A total of 736 ± 13 proteins in non-treated control group and 741 ± 19 protein spots in HU-treated cells were detected, of which 34 proteins (17 up-regulated and 17 down-regulated) exhibited significantly altered protein expression levels. Their physiological roles are mainly associated with cellular components, molecular functions, and biological processes by gene ontology analysis, among which 21 proteins were mapped to KEGG pathways. They are involved in 5 primary pathways with the subsets involving 16 secondary pathways by further KEGG analysis. More interestingly, the up-regulation of translationally controlled tumor protein was further identified to be associated with p12 degradation by Western blot analysis. Our works may enlarge and broaden our view for deeply understanding how global cellular stress responds to DNA damage, which could contribute to the etiology of human cancer or other diseases that can result from loss of genomic stability.

Prognostic value of PDCD6 polymorphisms and the susceptibility to bladder cancer

Programmed cell death 6 (PDCD6) has recently been found dysregulated in tumors of various origin. The aim of this study is to explore the association between PDCD6 genetic polymorphisms and susceptibility to bladder cancer and survival of patients with bladder cancer. Two tag SNPs of PDCD6, rs3756712 and rs4957014, were genotyped in 332 patients with bladder cancer and 509 controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and correlated with patients' survival. The frequencies of G allele and GG genotype of rs3756712 in patients were significantly lower than that of controls (P = 0.001, odds ratio [OR] = 0.68 for G allele; P = 0.024, OR = 0.53 for GG genotype in the recessive genetic model, respectively). The GT genotype of rs4957014 was associated with decreased susceptibility to bladder cancer in the overdominant genetic model (P = 0.023, OR = 0.72). Kaplan-Meier curves revealed a significant higher risk for death in superficial bladder cancer patients harboring GG homozygous of rs3756712 (P < 0.001), and an increased risk for recurrence in invasive bladder cancer patients carrying GT heterozygous of rs4957014 (P = 0.04). Multiple Cox regression analysis identified rs3756712 GG genotype as an independent prognostic factor for death in superficial bladder cancer patients (hazard ratio [HR] = 5.11, P = 0.01), and rs4957014 GT genotype as an independent prognostic factor for recurrence in invasive bladder cancer patients (HR = 1.93, P = 0.03). PDCD6 may represent a biomarker candidate gene that could help to identify a group of patients at high risk for recurrence and death.

Association between two single nucleotide polymorphisms of PDCD6 gene and increased endometriosis risk

Programmed cell death 6 (PDCD6), a calcium binding protein of the penta EF-hand protein family, and its receptors are involved in regulation of apoptosis pathways. To evaluate the relationship between genetic polymorphisms of PDCD6 gene and endometriosis (ED) risk, we investigated the association of two single nucleotide polymorphisms (SNPs) of PDCD6 gene (rs4957014 and rs3756712) in 220 endometriosis patients and 386 unrelated healthy controls. The genotypes of these two SNPs were determined by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and DNA sequencing methods. Significantly increased endometriosis risk was observed to be associated with G allele of rs4957014 locus (OR=1.31, 95% CI=1.03-1.69). We have also observed increased ED risk was statistically associated with rs4957014 polymorphism in a dominant model (OR=1.52, 95% CI=1.09-2.13). Although no association has been found between ED risk and the allele frequencies of rs3756712 locus (a marginal P=0.066, OR=1.27, 95% CI=0.98-1.65), but in a dominant model, increased endometriosis risk was significantly associated with rs3756712 polymorphism (OR=1.54, 95% CI=1.11-2.17). In conclusion, the current study indicates that PDCD6 gene may be a new susceptibility gene to endometriosis.