Program death 1 (PD1) haplotyping in patients with breast carcinoma

Associations of PD-1 and PD-L1 gene polymorphisms with cancer risk: a meta-analysis based on 50 studies

Programmed death-1 and its ligand-1 (PD-1/PD-L1), immune checkpoints proteins, play a crucial role in anti-tumor responses. A large number of studies have evaluated the relationships of PD-1/PD-L1 polymorphisms with risk of cancer, but evidence for the associations remains inconsistent. Therefore, we performed a meta-analysis to examine the associations between PD-1/PD-L1 single nucleotide polymorphisms (SNPs) and cancer predisposition. Results showed that PD-1.3 and PD-L1 rs17718883 were significantly correlated with overall cancer risk. PD-1.5 was prominently linked with cervical cancer (CC), non-small cell lung cancer (NSCLC), TC (thyroid cancer), brain tumor, AML (acute myelocytic leukemia) and UCC (urothelial cell carcinoma) risk, PD-1.9 with breast cancer (BC), AML, esophageal cancer (EC) and ovarian cancer (OC) risk, and PD-1.3 with colorectal cancer (CRC) and BCC (basal cell carcinoma) risk. PD-1.1 polymorphism slightly elevated BC and OC susceptibility, whereas the rs4143815 variant notably decreased the risk of gastric cancer (GC), hepatocellular carcinoma (HCC) and OC, but increased the risk of BC. PD-1.6 was closely linked with AML risk, PD-L1 rs2890658 with NSCLC, HCC and BC risk, rs17718883 with HCC and GC risk, rs10815225 with GC risk, and rs2297136 with NSCLC and HCC risk. Interestingly, the rs7421861, rs10815225, and rs10815225 markedly reduced cancer susceptibility among Asians. The rs7421861 polymrophism decreased cancer risk among Caucasians, rather than the rs10815225 elevated cancer risk. Our results supported that PD-1 and PD-L1 SNPs were dramatically correlated with cancer risk.

The PD-1 single-nucleotide polymorphism rs11568821 and rs2227981 as a novel prognosis model in a triple-negative breast cancer patient

INTRODUCTION

The aim of the study is to determine the relationship between polymorphisms rs11568821 C/T and at rs2227981 G/A in the programmed cell death 1 gene (PDCD1) and the clinicopathologic characteristics of triple negative breast cancer patient (TNBC).

MATERIAL AND METHODS

The study included 30 TNBC patients and 30 healthy controls. Genotyping was performed with allelic discrimination using PCR with TaqMan SNP Genotyping Assays.

RESULTS

The presence of CC/CT in rs11568821and GG/AG in rs2227981 were not associated with the risk of progression of TNBC. The correlation between rs11568821 minor allele distribution and risk of TNBC has borderline significance (p = 0.0619). The rs2227981 polymorphism has a significant association with grade G (G3, p = 0.0229). There was a trend toward significance (p = 0.063448) in the minor allele presentation and Ki67 > 20% for rs2227981. Other clinical features (e.g. age, TNM stage) did not significantly correlate with the rs11568821 or the rs2227981 polymorphism.

CONCLUSION

rs2227981 is associated with grading; hence PDCD1 can be used as a prognostic marker in TNBC.

Association of programmed cell death 1 (PD-1) gene polymorphism (rs10204525) with COVID-19 severity and mortality: A case-control study in the Iranian population

BACKGROUND

Programmed cell death 1 (PD-1), as a negative immune regulator, regulates the activation of T cells and maintains the immune system's homeostasis. Previous studies suggest that the effective immune response against COVID-19 contributes to the outcome of the disease. The present study aims to evaluate whether the PD-1 rs10204525 polymorphism is associated with PDCD-1 expression and COVID-19 severity and mortality in the Iranian population.

METHODS

The PD-1 rs10204525 was genotyped in 810 COVID-19 patients and 164 healthy individuals as a control group using Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Moreover, we assessed the expression of PDCD-1 in peripheral blood nuclear cells by real-time PCR.

RESULTS

Regarding disease severity and mortality, no significant differences were detected between study groups in alleles and genotypes frequency distribution under different inheritance models. We found that the expression of PDCD-1 was significantly lower in COVID-19 patients with AG and GG genotypes than in the control group. Regarding disease severity, mRNA levels of PDCD-1 were significantly lower in moderate and critical patients carrying AG genotype than in control (P = 0.005 and P = 0.002, respectively) and mild (P = 0.014 and P = 0.005, respectively) individuals. Additionally, the severe and critical patients with GG genotype displayed a significantly lower level of PDCD-1 compared with the control (P = 0.002 and P < 0.001, respectively), mild (P = 0.004 and P < 0.001, respectively), and moderate (P = 0.014 and P < 0.001, respectively) ones. Regarding disease mortality, the expression of PDCD-1 was significantly lower in non-survivor COVID-19 patients with GG genotype than in survivors.

CONCLUSION

Considering the lack of significant differences in PDCD-1 expression in different genotypes in the control group, lower expression of PDCD-1 in COVID-19 patients carrying the G allele suggests the impact of this single-nucleotide polymorphism on the transcriptional activity of PD-1.

The association between PD-1 gene polymorphisms and susceptibility to multiple sclerosis

Programmed cell death 1 (PD-1) is an immune checkpoint and has been reported to be associated with several autoimmune diseases. We aimed to investigate the association between human PD-1 gene (PDCD1) polymorphisms and multiple sclerosis (MS). This case-control study was conducted on 229 MS patients and 246 healthy controls. Genotyping of rs36084323 (PD-1.1 G/A), rs11568821 (PD-1.3 G/A) and rs2227981 (PD-1.5 C/T) polymorphisms was performed by PCR-RFLP technique. The frequency difference of PD-1.1 genotypes and alleles (-536 G/A) between patients and healthy controls was not significant. Regarding PD-1.3, the AA + AG genotype was found to be relatively higher in the control group. Concerning PD-1.5 (+7785 C/T), the frequency of T allele carriers (TT + CT) was relatively higher in MS patients, which was marginally insignificant (p = .07). PD-1 gene polymorphisms may be associated with MS; however, accurate conclusions require further studies with a larger number of samples.

Pilot Study: Immune Checkpoints Polymorphisms in Greek Primary Breast Cancer Patients

Background: Breast cancer is the most prevalent and second leading cause of cancer-related death in women worldwide. Despite early detection and better treatment therapies, 30% of early-stage breast cancer patients still develop recurrent disease. Breast cancer is a heterogeneous disease comprising several molecular subtypes, commonly classified into clinical subtypes based on the hormone receptor status. These subtypes included luminal A and luminal B, which have different prognoses. Breast cancer development and progression involve many factors. Polymorphisms of PD-1, PD-L1, and PD-L2 genes have been previously associated with high risk and prognosis of cancer. However, no studies have associated PD-1, PD-L1, and PD-L2 polymorphisms with primary breast cancer subtypes. Hence, this study evaluated functional single nucleotide polymorphisms of PD-1, PD-L1, and PD-L2 with primary breast cancer subtypes, luminal A, and luminal B. In addition, we evaluated the PD-L1 protein expression in relation to primary breast cancer subtypes and stages. Results: There were no significant differences in the allele frequencies of PD-1 polymorphisms (rs2227981 G>A, rs7421861 A>G, and rs11568821 C>T) and PD-L1 polymorphisms (rs10815225 C>T and rs2282055 T>G) when compared with the general European population. However, a significant difference was detected in one of the PD-L2 polymorphisms (rs1009759 A>G), with the G allele higher in breast cancer patients than in the general European population. A higher prevalence of the T allele of PD-L1 polymorphism rs2282055 T>G was observed in luminal B breast cancer patients compared with luminal A. No significant difference was detected in other polymorphisms. We also observed that the PD-L1 rs2282055 TT genotype was more prevalent in luminal B breast cancer patients compared with luminal A. Our results found no association of the selected SNPs in the PDCD1 gene with breast cancer risk. Similarly, the protein expression data showed that PD-L1 and PD-L2 are associated with an aggressive phenotype, Luminal B, and advanced breast cancer stage. Conclusion: These findings suggest that immune checkpoint polymorphisms are associated with the risk and subtypes of breast cancer.

Screening of Immune-Related Genes and Predicting the Immunotherapeutic Effects of Formononetin in Breast Cancer: A Bioinformatics Analysis

Objective

Immunotherapy is a promising breast cancer treatment. Nonetheless, tumor heterogeneity and the interaction between immune cells in the tumor microenvironment limit its effectiveness. Formononetin—extracted from the Chinese medicinal plant Astragalus membranaceus—can inhibit tumor growth, induce apoptosis and angiogenesis, and reverse multidrug resistance. However, its efficacy and mechanism of action on the immune cells in breast cancer remain unclear. Here, we screened immune-related genes of breast cancer to determine the potential of formononetin as a therapeutic.

Methods

GSE103512 and GSE139038 breast cancer microarray data and immune-related gene data were obtained from the GEO and ImmPort databases, respectively, to analyze the differentially expressed immune-related genes (IRGs) in breast cancer tissues compared with normal breast tissues. Protein-protein interaction (PPI) analysis was performed using the STRING database to screen differentially expressed IRGs based on the topological parameters. The Kaplan–Meier test was applied to detect differentially expressed IRGs associated with breast cancer survival, and the interaction of formononetin with differentially expressed IRGs was analyzed using molecular docking. Finally, the relationship between differentially expressed IRGs and breast cancer immune cell infiltration was analyzed using the TIMER2.0 database.

Results

A total of 29 differentially expressed IRGs of breast cancer were screened through GEO and ImmPort databases and 10 key differentially expressed IRGs based on the topological parameters from the PPI network. Among these, CXCL12, ESR1, IGF1, and FOS were associated with breast cancer survival. Furthermore, IGF1, ESR1, and CXCL12 were found to have stable binding sites for formononetin. These genes were associated with substantial immune cell infiltration in breast cancer tissues.

Conclusion

In conclusion, formononetin may exert antitumor effects by acting on CXCL12, ESR1, and IGF1 and may have a potential synergistic effect with immune checkpoint inhibitors.

Relationship of Programmed Death-1 (PD-1) and Programmed Death Ligand-1 (PD-L1) Polymorphisms with Overall Cancer Susceptibility: An Updated Meta-Analysis of 28 Studies with 60 612 Subjects

Background

Programmed death-1 and its ligand-1 (PD-1/PD-L1) regulate tumor immunotherapy. A large number of studies have explored the relationship between PD-1, PD-L1, and different tumor susceptibility. However, these conclusions are not always consistent. Therefore, we updated this meta-analysis.

Material/Methods

MEDLINE, Web of Science, EMBASE and other databases were searched systematically to obtain related research. Then, we used STATA15.0 software to carry out the final meta-analysis. The computational advantage is better than OR to evaluate this relationship.

Results

A total of a total of 28 related studies were involved in our meta-analysis. It was found that PD-1 rs11568821 and rs7421861 increased the overall cancer probability in the allelic genetic model, while PD-1 rs36084323 effectively reduced the risk of cancer in the dominant genetic model. In the homozygous genetic model, PD-L1 rs17718883 effectively increased the probability of tumorigenesis. PD-L1rs4143815 is associated with a reduced incidence of cancer in heterozygote, homozygote and dominant genetic patterns. Subgroup analysis showed that PD-1rs2227981 can promote the susceptibility to breast cancer, while PD-1rs2227982 can reduce the susceptibility to breast cancer. PD-L1 rs2890658 can significantly reduce the risk of lung and liver cancer.

Conclusions

PD-1rs11568821, rs36084323, rs7421861, pD-L1rs17718883, and rs4143815 are associated with tumor susceptibility. However, a review based on more experimental evidence is needed to verify our findings.

The roles of PD-1/PD-L1 in the prognosis and immunotherapy of prostate cancer

Multiple studies have confirmed that programmed cell death 1/programmed cell death ligand-1 (PD-1/PD-L1) and immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 play pivotal roles in the treatment of numerous tumors. Patients suffering from cancer are provided hope in the form of immunotherapy. In this review, we discuss the finding that high PD-L1 expression is associated with poor clinical outcomes in prostate cancer patients. Some molecules exert their antitumor effects by downregulating PD-L1 expression in prostate cancer. Additionally, we discuss and summarize the important roles played by anti-PD-1/PD-L1 immunotherapy and its combination with other drugs, including chemotherapy and vaccines, in the treatment of prostate cancer.

Immune Checkpoint Molecules-Inherited Variations as Markers for Cancer Risk

In recent years, immunotherapy has been revolutionized by a new approach that works by blocking receptors called immune checkpoints (IC). These molecules play a key role in maintaining immune homeostasis, mainly by suppressing the immune response and by preventing its overactivation. Since inhibition of the immune response by IC can be used by cancer to avoid recognition and destruction by immune system, blocking them enhances the anti-tumor response. This therapeutic approach has brought spectacular clinical effects. The ICs present heterogeneous expression patterns on immune cells, which may affect the effectiveness of immunotherapy. The inherited genetic variants in regulatory regions of ICs genes can be considered as potential factors responsible for observed inter-individual differences in ICs expression levels on immune cells. Additionally, polymorphism located in exons may introduce changes to ICs amino acid sequences with potential impact on functional properties of these molecules. Since genetic variants may affect both expression and structure of ICs, they are considered as risk factors of cancer development. Inherited genetic markers such as SNPs may also be useful in stratification patients into groups which will benefit from particular immunotherapy. In this review, we have comprehensively summarized the current understanding of the relationship between inherited variations of CTLA-4, PDCD1, PD-L1, BTLA, TIM-3, and LAG-3 genes in order to select SNPs which can be used as predictive biomarkers in personalized evaluation of cancer risk development and outcomes as well as possible response to immunotherapy.

Evaluating the Possible Association between PD-1 (Rs11568821, Rs2227981, Rs2227982) and PD-L1 (Rs4143815, Rs2890658) Polymorphisms and Susceptibility to Breast Cancer in a Sample of Southeast Iranian Women

INTRODUCTION

Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) play a critical role as a  regulator of immune-system cells, including T cell, natural killer T (NKT), monocytes, dendritic cells (DC), and B cells.

OBJECTIVE

This study aimed to find a possible association between PD-1 (rs11568821, rs2227981, rs2227982), and PD-L1 (rs4143815, rs2890658) variants and Breast Cancer (BC) risk in a sample of southeast Iranian women.

METHOD

The case-control study consisted of 520 individuals, including 260 histologically confirmed BC patients and 260 non-cancer age-matching healthy women as the control group. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Tetra-Primer Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS-PCR) methods were used for genotyping of PD-1 (rs11568821, rs2227981, rs2227982), and PD-L1 (rs4143815, rs2890658) polymorphisms.

RESULTS AND CONCLUSION

Our findings indicated that the PD-L1 rs4143815 (G/C) variant meaningfully reduced the risk of BC. However, the PD-L1 rs2890658 variant increased the BC risk in the AC genotype as well as the A allele. Furthermore, we could not find a meaningful association between PD-1 rs11568821, PD-1 rs2227981, PD-1 rs2227982, and BC. Our team examined the possible association between variants and clinicopathological characteristics, including age, size of tumour, lymph node, histology, grade of tumour, estrogen and progesterone receptors status as well as human growth factor receptor 2 (HER2). Our findings demonstrated that PD-L1 rs4143815, PD-L1 rs2890658, PD-1 rs2227982 had a significant association with age. Additionally, we found a significant relation between PD-1 rs2227982 variant and tumour size. Statistical analyzes of PD-1 rs2227981 and PD-1 rs11568821 variants showed a meaningful relation between tumour grade and tumour stage (p=0.006), respectively.<br />.

PD-1 gene rs10204525 and rs7421861 polymorphisms are associated with increased risk and clinical features of esophageal cancer in a Chinese Han population

Programmed death-1 (PD-1) polymorphisms have been associated with esophageal cancer risk. Here, the aims of this case-control study were to explore whether three PD-1 polymorphisms (rs10204525, rs7421861, and rs36084323) were related with the risk and clinical features of esophageal cancer in Chinese Han subjects (n = 814 cases and 961 controls). We found that rs10204525 and rs7421861, but not rs36084323, conferred increased susceptibility to esophageal cancer. Subgroup analysis revealed that all three loci increased the risk of esophageal cancer among men, and that rs10204525 and rs7421861 correlated with increased risk among patients ≥ 60 years old. The rs10204525 and rs7421861 polymorphisms were associated with higher TNM stage, and rs10204525 was associated with distant metastasis. The combination of smoking and either the rs10204525 or rs7421861 genotype conferred an increased risk to esophageal cancer, which is indicative of potential gene-environment interactions. The rs10204525 and rs7421861 polymorphisms correlated with increased PD-1 gene and protein levels, and Kaplan-Meier survival curves showed higher PD-1 gene expression was related to poorer overall survival. These data indicate the rs10204525 and rs7421861 polymorphisms of PD-1 gene confer an increased risk of esophageal cancer among Chinese Han individuals.

Association between PD-1 and PD-L1 Polymorphisms and the Risk of Cancer: A Meta-Analysis of Case-Control Studies

A number of case-control studies regarding the association of the polymorphisms in the programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) genes with the risk of cancer have yielded inconsistent findings. Therefore, we have conducted a comprehensive, updated meta-analysis study to identify the impact of PD-1 and PD-L1 polymorphisms on overall cancer susceptibility. The findings revealed that PD-1 rs2227981 and rs11568821 polymorphisms significantly decreased the overall cancer risk (Odds Ratio (OR) = 0.82, 95% CI = 0.68–0.99, p = 0.04, TT vs. CT+CC; OR = 0.79, 95% CI = 0.67–0.94, p = 0.006, AG vs. GG, and OR = 0.82, 95% CI = 0.70–0.96, p = 0.020, AG+AA vs. GG, respectively), while PD-1 rs7421861 polymorphism significantly increased the risk of developing cancer (OR = 1.16, 95% CI = 1.02–1.33, p = 0.03, CT vs. TT). The PD-L1 rs4143815 variant significantly decreased the risk of cancer in homozygous (OR = 0.62, 95% CI = 0.41–0.94, p = 0.02), dominant (OR = 0.70, 95% CI = 0.50–0.97, p = 0.03), recessive (OR = 0.76, 95% CI = 0.60–0.96, p = 0.02), and allele (OR = 0.78, 95% CI = 0.63–0.96, p = 0.02) genetic models. No significant association between rs2227982, rs36084323, rs10204525, and rs2890658 polymorphisms and overall cancer risk has been found. In conclusions, the results of this meta-analysis have revealed an association between PD-1 rs2227981, rs11568821, rs7421861, as well as PD-L1 rs4143815 polymorphisms and overall cancer susceptibility.

Association of programmed death-1 gene polymorphisms with the risk of basal cell carcinoma

Environmental and genetic factors play a fundamental role in the pathogenesis of basal cell carcinoma (BCC) defined as the most common cancer of skin. Programmed death-1 (PD-1), encoded by programmed cell death-1 (PDCD1) gene, serves as an inhibitory molecule in the suppression of immune responses and a risk factor in the development of different cancers. In this study, we investigated the role of two single nucleotide polymorphisms (SNPs) within PDCD1 gene, and haplotypes defined by these SNPs, in the development of BCC in an Iranian population. Whole blood samples were obtained from 210 BCC and 320 healthy subjects. Genomic DNA was extracted from whole blood samples, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype determinations of PD1.3 (rs11568821) and PD1.5 (rs2227981) SNPs, and 4 haplotypes were constructed by PDCD1 SNPs. The frequency of G allele of PD1.3 was significantly higher in BCC patients than healthy subjects (p < 0.02), while these significant differences were not observed in the frequencies of PD1.5 alleles between BCC and healthy subjects. Moreover, we found that there were no statistically significant differences in PD1.3 and PD1.5 genotypes between BCC and control groups. Of all estimated haplotypes for PDCD1, only AC haplotype was associated with BCC (OR = 0.22, 95% CI = 0.06-0.79, p < 0.01). These findings suggest that PD1.3G allele and AC haplotype of PDCD1 contribute to BCC in the Iranian population. However, further studies in different populations with larger sample size are required to confirm this study.

PD-1 Haplotype Combinations and Susceptibility of Patients to Squamous Cell Carcinomas of Head and Neck

INTRODUCTION

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of head and neck and the sixth most common malignancy worldwide. Programmed cell death 1 (PD-1) is an immune inhibitory molecule which through interaction with its ligands recruits protein phosphatase resulting in immune response inhibition. Expression of PD-1 ligands on tumor cells is considered as one of the crucial immune evasion mechanisms. This study aimed to investigate the association of PD-1 gene polymorphisms at positions PD1.3 (rs11568821), PD1.5 (rs2227981) and PD1.9 (rs2227982) with susceptibility to HNSCCs.

SUBJECTS AND METHODS

150 patients pathologically confirmed to suffer from HNSCCs and 150 age-sex matched healthy controls were recruited in this study. Genomic DNA was extracted from white blood cells of all participants. Restricted fragment length polymorphisms (RFLP)-PCR was performed using site specific primers to determine the genotypes in each position.

RESULTS

Statistical analyses indicated no significant differences in the frequencies of genotypes, alleles as well as haplotypes between patients and controls (P > 0.05), however, haplotype combination differed significantly between two groups. GCC/GCT, GCC/GCC and GCT/GCC were higher in the HNSCC patients than the control group (P < 0.05). On the other hand, in the controls, GCT/GCT, GCT/ACC, GCT/ACT and ACC/GCT were more frequent. No significant association was found with various HNSCC clinicopathological characteristics.

DISCUSSION

Our results suggested that although PD-1 gene polymorphisms at three investigated positions are not solely associated with susceptibility to HNSCCs, haplotype combinations emerged from these three loci may render susceptibility.

Association of PD-1 gene with outcome of hepatitis C virus infection

Primary hepatitis C virus infection might be spontaneously cleared or become chronic. Polymorphisms in immune regulatory genes might influence the outcome. The aim of this study was to determine the frequency of genotypes and alleles of PD-1.3 and PD-1.5 gene loci in HCV infected patients and their association with the disease outcome. In this study 167 patients with chronic hepatic C and 42 individuals whose infection was spontaneously cleared, and a healthy control group comprising of 300 participants were included. The presence of chronic or spontaneously cleared infection amongst the participants was determined in advance by serologic and molecular methods. Genomic DNA was extracted using salting out method. PD-1 gene polymorphisms assay was performed using PCR-RFLP method. The frequency of alleles of PD-1.3 gene locus was significantly higher in the spontaneously cleared HCV infected group (P = 0.03) as well as the healthy control group (P = 0.04) in comparison to the chronic infected participants. In the case of PD-1.5 locus, there was no association between the frequency of inherited genotype or alleles and HCV infection outcome amongst the three groups. Haplotype analysis showed no statistically significant differences in the frequencies of different haplotypes between the three studied groups. Our finding collectively inferred that individuals with A allele at PD-1.3 locus might clear HCV infection more frequently than those with T allele. Instead, polymorphisms at PD-1.5 locus as well as haplotypes emerged from PD-1.3 G/A and PD-1.5 C/T might not be significant in the HCV infection outcome.

PD-1 and cancer: molecular mechanisms and polymorphisms

The programmed cell death protein 1 (PD-1) is expressed by activated T cells that act as an immunoregulatory molecule, and are responsible for the negative regulation of T cell activation and peripheral tolerance. The PD-1 gene also encodes an inhibitory cell surface receptor involved in the regulation of T cell functions during immune responses/tolerance. Beyond potent inhibitory effects on T cells, PD-1 also has a role in regulating B cell and monocyte responses. An overexpression of PD-1 has been reported to contribute to immune system avoidance in different cancers. In particular, PD-1 over-expression influences tumor-specific T cell immunity in a cancer microenvironment. Blocking the PD-1/PD-1 ligand (PD-L1) pathway could potentially augment endogenous antitumor responses. Along these lines, the use of PD-1/PD-L1 inhibitors has been applied in clinical trials against diverse forms of cancer. It was believed that antibodies targeting PD-1/PD-L1 might synergize with other treatments that enhance endogenous antitumor immunity by blocking inhibitory receptor-ligand interactions. However, in all cases, the host genetic status (as well as that of the tumor) is likely to have an impact on the expected outcomes. Various investigations have evaluated the association between PD-1 polymorphisms and the risk of various types of cancer. Frequently studied PD-1 polymorphisms, PD-1.1 (rs36084323), PD-1.3 (rs11568821), PD-1.5 (rs2227981), PD-1.9 (rs2227982), and PD-1 rs7421861, and their associations in the risk of susceptibility to different types of cancer are mentioned in this review, as are studies highlighting the significance of conducting genetic association studies in different ethnic populations.

Soluble PD-1 and PD-L1: predictive and prognostic significance in cancer

The membrane-bound molecules programmed death 1 (PD-1) and its ligand PD-L1 (PD-1/PD-L1) belong to the immune checkpoint pathway. PD-1 pathway downregulates effector T cells in immune response, thereby causing immune suppression. Recent studies have revealed that membrane-bound PD-1 and PD-L1 also have soluble forms. These soluble forms increase the complexity and diversity of the composition and function of the PD-1/PD-L1 signaling pathway. However, the exact roles of these molecules remain unknown. The objective of this systematic review was to elucidate the biological significance of soluble PD-1/PD-L1 in human cancers and evaluate whether they are potential diagnostic, therapeutic, or prognostic biomarkers. We expect to provide new clues for future research on soluble PD-1/PD-L1 pathway in human malignant tumors.

Association of PD-1.5 C/T, but Not PD-1.3 G/A, with Malignant and Benign Brain Tumors in Iranian Patients

Programmed death-1 (PD-1) negatively regulates the immune response. The aims of this study were to assess the association of two single nucleotide polymorphisms in the PD-1 gene, PD-1.5 (+7785 C/T-rs2227981) and PD-1.3 (+7146 G/A- rs11568821), with benign and malignant brain tumors. Patients with brain tumors (96 patients with benign and 56 with malignant brain tumors) and 150 healthy control individuals were included. PCR-RFLP was performed for genotyping. It was revealed that the genotype and allele frequencies of PD-1.5 C/T polymorphism were significantly different between all brain tumor patients and the control group. The frequencies of the CT genotype and T allele were higher in brain tumor patients. In contrast, the frequency of PD-1.3 G/A genotypes and alleles showed no significant difference between all brain tumor patients and controls. Patients were then divided into malignant and benign groups. The results revealed a significant difference in both patients groups compared with the controls only at PD-1.5 C/T position. Arlequin analysis showed the GC haplotype was the most frequent haplotype in the whole group of patients and controls, and the GT haplotype was significantly different between patient and control groups. In conclusion, we demonstrate that PD-1.5 C/T polymorphism, but not PD-1.3 G/A, is associated with brain tumors in Iranian patients.

Association of PDCD1 gene markers with susceptibility to thyroid cancer

PURPOSE

PD-1 receptor is a co-signaling molecule with an important role in regulation of T-lymphocyte activity. Correlation between PD-1 gene (PDCD1) polymorphisms and some immune-related diseases has been reported before. In current study, we aimed to investigate the association of PD-1 polymorphisms at positions +7146 G/A (PD-1.3) and +7785 C/T (PD-1.5), as well as the emerged haplotypes with susceptibility to thyroid carcinoma.

METHODS

One hundred five patients with confirmed thyroid cancer and 160 healthy individuals as control group were enrolled. Genotypes were identified using PCR-RFLP and nested PCR-RFLP methods. Results were analyzed by Arlequin and SPSS software packages.

RESULTS

Analysis revealed a significant increase in the frequency of PD-1.5 mutant T allele and heterozygous CT genotype in patients with thyroid cancer in comparison with controls [79 (37.7%) vs. 71 (22.2%), and 51 (48.6%) vs. 51 (31.9%), p = 0.0001 and p = 0.009, receptively]. CC genotype at this position observed to be significantly higher among controls than the patients [99 (61.9%) vs. 40 (38.1%), p = 0.0002]. There were no significant differences in the frequencies of genotypes and alleles at locus PD-1.3 between patients and control group. Despite this, GT haplotype emerged from both positions (PD-1.3 G and PD-1.5 T) has also been observed with significant increased frequency between patients and controls [70 (36.8%) vs. 71 (22.2%), p = 0.0005].

CONCLUSION

As the first study to investigate two mentioned polymorphisms in thyroid cancer, current study confirmed the association of PD-1.5 C/T polymorphism and a haplotype resulted from both loci, PD-1.3 and PD-1.5, with susceptibility of Iranians to thyroid cancer.

The effect of polymorphisms in PD-1 gene on the risk of epithelial ovarian cancer and patients' outcomes

OBJECTIVE

Programmed death-1 (PD-1), an important immunosuppressive molecule, plays a key role in tumor-cell-mediated immune escape. In the present study, we evaluated the effect of PD-1 gene polymorphisms on the risk of developing epithelial ovarian cancer (EOC) and patients' outcomes.

METHODS

A case-control study was performed in 620 EOC patients and 620 control women. Survival data were available for 258 patients who received platinum-based chemotherapy after cytoreductive surgery.

RESULTS

There were significant differences in the genotype and allele distribution frequencies of the PD-1.1 A/G between cases and controls (P=0.028 and P=0.02, respectively). Compared with the AA genotype, AG and GG genotypes may significantly decrease the risk of developing EOC (OR=0.71, 95%CI=0.54-0.94; OR=0.68, 95%CI=0.50-0.94, respectively). We did not find a significant difference in the genotype distribution frequency of the PD-1.5 C/T between cases and controls (P=0.096), but the frequency of T alleles was significantly lower in the EOC cases than that in the controls (P=0.033). Compared to the carriers with C alleles, the carriers with T alleles were at a significantly decreased risk of developing EOC (OR=0.82, 95%CI=0.69-0.98). Survival analysis showed that the two polymorphisms were not associated with patients' outcomes.

CONCLUSIONS

PD-1 gene polymorphisms may be involved in the development of EOC, but not associated with its clinical outcome in EOC patients among northern Chinese women.

The association between polymorphisms in the PDCD1 gene and the risk of cancer: A PRISMA-compliant meta-analysis

BACKGROUND

The effects of the programed cell death 1 (PDCD1) gene polymorphisms on cancer risk have been investigated in some studies; however, the results were conflicting and ambiguous. Therefore, we aimed to do a meta-analysis to investigate the association of PDCD1 polymorphisms with cancer risk from all eligible case-control studies.

MATERIALS AND METHODS

An electronic search of the PubMed, Embase, Chinese National Knowledge Infrastructure, and Wanfang databases was performed. The association between PDCD1 polymorphisms with cancer risk was calculated with odds ratios (ORs) and their corresponding 95% of confidence intervals (CIs).

RESULTS

A total of 24 case-control studies from 13 articles that investigated the associations of 5 widely studied polymorphisms in PDCD1 gene and cancer risks were included. The results of meta-analysis: the PDCD-1.5 (rs2227981) and PDCD-1.3 (rs11568821) polymorphisms were associated with decreased risk of cancer (rs2227981: OR = 0.75, 95% CI: 0.64-0.86, P < 0.0001 for TT vs TC + CC; rs11568821: OR = 0.79, 95% CI: 0.65-0.96, P = 0.02 for TC vs TT), while no significant associations were found for the other 3 polymorphisms (PDCD-1.9 [rs2227982] polymorphism: OR = 1.03, 95% CI: 0.90-1.18, P = 0.66 for CC + TC vs TT; PDCD1 rs7421861 polymorphism: OR = 1.10, 95% CI: 0.96-1.25, P = 0.16 for CC + TC vs TT; PDCD-1.6 [rs10204525] polymorphism: OR = 0.93, 95% CI: 0.82-1.05, P = 0.24 for GG + GA vs AA).

CONCLUSION

The meta-analysis suggests that the PDCD-1.5 (rs2227981) and PDCD-1.3 (rs11568821) polymorphisms are associated with susceptibility of cancer. Further studies with larger sample sizes are required to make a better assessment of the above association.

Association of programmed death-1 polymorphisms with the risk and prognosis of esophageal squamous cell carcinoma

Programmed death-1 (PD-1) is an immunoinhibitory receptor belonging to the CD28 family. This study was designed to investigate the association of PD-1 rs36084323:A>G, rs2227981:C>T, rs2227982:C>T and rs10204525:A>G single nucleotide polymorphisms (SNPs) with the risk and prognosis of esophageal squamous cell carcinoma (ESCC) in a high-incidence population from Northern China. These four SNPs were genotyped by polymerase chain reaction ligase detection reaction (PCR-LDR) method in 584 ESCC patients and 585 healthy controls. The rs2227981:C>T SNP C/T genotype increased the risk of ESCC for the smokers (OR = 1.483, 95% CI = 1.018-2.160) and rs2227982:C>T SNP C/T genotype enhanced susceptibility to ESCC for the females (OR = 1.708, 95% CI = 1.056-2.762). For rs10204525:A>G SNP, A/A genotype was related to increased risk of ESCC (OR = 1.735, 95% CI = 1.086-2.771) overall. Among the 584 ESCC patients, the survival information of 204 ESCC patients was collected. The rs36084323:A>G SNP A/G genotype was associated with lower risk of death in ESCC patients with upper gastrointestinal cancer (UGIC) family history (HR = 0.339, 95%CI = 0.115-0.996). The rs2227982:C>T SNP C/T genotype was associated with lower risk of death in smoker ESCC patients and ESCC patients with UGIC family history (HR = 0.409 and 0.292, 95%CI = 0.194-0.863 and 0.101-0.847). PD-1 rs2227981:C>T, rs2227982:C>T and rs10204525:A>G SNPs might be used as predictive markers of the susceptibility to ESCC for the Han nationality in a high-incidence population from Northern China. PD-1 rs36084323:A>G and rs2227982:C>T SNPs were associated with the prognosis of the Han ESCC patients in this high-incidence region.

PD-1 rs2227982 Polymorphism Is Associated With the Decreased Risk of Breast Cancer in Northwest Chinese Women: A Hospital-Based Observational Study

Programmed death-1 (PD-1) is crucial in cancer and is well characterized as a negative T-cell regulator that functions by delivering inhibitory signals. We aimed to evaluate the relationship between PD-1 polymorphisms (rs10204525, rs2227982, and rs7421861) and breast cancer risk.We selected 560 breast cancer patients and 583 age-, sex-, and ethnicity-matched healthy controls from Northwest China. The PD-1 polymorphisms were genotyped by using Sequenom MassARRAY. Associations were estimated with odds ratios (ORs) and 95% confidence intervals (95% CIs).For the rs10204525 and rs7421861 polymorphisms, no differences in breast cancer risk were found in any of the genetic models. For the rs2227982 polymorphism, the variant genotypes were significantly associated with decreased breast cancer risk (CT vs CC: OR = 0.68, 95% CI = 0.52-0.91; CT + TT vs CC: OR = 0.69, 95% CI = 0.53-0.90). In analyses stratified by age, the decreased risk was observed among the younger subjects (OR = 0.68, 95% CI = 0.47-0.97). We found that the decreased risk observed for the variant genotypes of rs2227982 was associated with the Her-2 status (CT vs CC: OR = 0.55, 95% CI = 0.37-0.84; CT + TT vs CC: OR = 0.56, 95% CI = 0.38-0.82). The haplotype analysis showed that the Ars10204525 Trs2227982 Crs7421861 haplotype was associated with a significantly decreased risk of breast cancer (OR = 0.50, 95% CI = 0.34-0.75).Our findings support an association between the PD-1 rs2227982 polymorphism and decreased breast cancer risk, especially in Her-2 positive breast cancer patients in the Chinese population.

Programmed Cell Death-1 Polymorphisms Decrease the Cancer Risk: A Meta-Analysis Involving Twelve Case-Control Studies

Programmed cell death-1 (PD-1) plays an important inhibitory role in anti-tumor responses, so it is considered as a powerful candidate gene for individual’s genetic susceptibility to cancer. Recently, some epidemiological studies have evaluated the association between PD-1 polymorphisms and cancer risk. However, the results of the studies are conflicting. Therefore, a meta-analysis was performed. We identified all studies reporting the relationship between PD-1 polymorphisms and cancers by electronically searches. According to the inclusion criteria and the quality assessment of Newcastle-Ottawa Scale (NOS), only high quality studies were included. A total of twelve relevant studies involving 5,206 cases and 5,174 controls were recruited. For PD-1.5 (rs2227981) polymorphism, significantly decreased cancer risks were obtained among overall population, Asians subgroup and population-based subgroup both in TT vs. CC and TT vs. CT+CC genetic models. In addition, a similar result was also found in T vs. C allele for overall population. However, there were no significant associations between either PD-1.9 (rs2227982) or PD-1 rs7421861 polymorphisms and cancer risks in all genetic models and alleles. For PD-1.3 (rs11568821) polymorphism, we found different cancer susceptibilities between GA vs. GG and AA vs. AG+GG genetic models, and no associations between AA vs. GG, AA+AG vs. GG genetic models or A vs. G allele and cancer risks. In general, our results firstly indicated that PD-1.5 (rs2227981) polymorphism is associated a strongly decreased risk of cancers. Additional epidemiological studies are needed to confirm our findings.

Targeting multiple pathways in breast cancer

SUMMARY Breast cancer (BC) is a highly prevalent disease. Worldwide, it is the most common cancer diagnosed and the leading cause of cancer death in women, making this disease a very important focus of interest and research. There is great heterogeneity in clinical outcomes among women diagnosed with BC, possibly indicating that biological heterogeneity is a major factor interfering with tumor development and progression. Presently, it is known that specific genetic expression patterns divide BC into distinct molecular subtypes. In fact, a better understanding of molecular profiles in BC and more advances in biological technology has divided each BC subtype further into additional subcategories. This means that more pathways are being recognized as important drivers or contributors to BC development and progression. The implication in BC treatment and management can be enormous. A more complete knowledge of the biology of the tumor has many implications. Development of therapies that specifically target the activated pathways can allow the delivery of more effective treatments and spare patients from treatments that would only cause side effects. This article will focus on exploring and reviewing the different molecular pathways involved in each clinically relevant BC subtype, namely hormone receptor-positive, HER2-positive and triple-negative BC. For each BC subtype, novel targeted therapies that are already incorporated in clinical practice, as well as drugs in clinical development, will be described, including the safety profiles of each one. We will highlight the major molecular pathways involved in each BC subtype, providing a rationale for the development of specific targeted therapies. Mechanisms of resistance to conventional therapies by pathway activation will be discussed. Strategies to overcome resistance are also a major focus of this review.

Lack of an association of programmed cell death-1 PD1.3 polymorphism with risk of hepatocellular carcinoma susceptibility in Turkish population: a case-control study

AIM

The programmed cell death-1 (PD-1) is a potent immunoregulatory molecule which is responsible for the negative regulation of T-cell activation and peripheral tolerance. Recently, overexpression of PD-1 has been reported to contribute to immune system evasion and poor survival of hepatocellular carcinoma (HCC). A common single nucleotide polymorphism in intron 4 of PD-1 gene called PD-1.3 has been reported to influence PD-1 expression, but its association with HCC has yet to be investigated. The aim of the present study was to investigate whether this polymorphism could be involved in the risk of HCC susceptibility.

METHODS

The genotype frequency of PD-1.3 polymorphism was determined by using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 236 subjects with HCC and 236 cancer-free control subjects matched on age, gender, smoking and alcohol status.

RESULTS

No statistically significant differences were found in the genotype distributions of the PD-1.3 polymorphism among HCC and cancer-free control subjects (P=0.22).

CONCLUSION

Our results demonstrate for the first time that the PD-1.3 polymorphism has not been in any major role in genetic susceptibility to hepatocellular carcinogenesis, at least in the population studied here. Independent studies are needed to validate our findings in a larger series, as well as in patients of different ethnic origins.

Programmed death-1 gene polymorphism (PD-1.5 C/T) is associated with colon cancer

Programmed death-1 (PD-1), expressed by activated T cells, is a negative regulator of T lymphocytes. The associations of the immune response-related genes with cancer have been demonstrated. In this study, the PD-1.5 C/T (+7785) polymorphism was investigated in 200 colorectal cancer patients and 200 healthy individuals as controls by nested polymerase chain reaction-restriction fragment length polymorphism method. The genotype and allele frequencies at PD-1.5 position were not significantly different between control individuals and the overall colorectal cancer patients. However, subdivision of the patients by the location (175 colon cancer and 25 rectal cancer) revealed a significant difference between colon cancer patients and healthy individuals (p=0.026), and between colon and rectal cancer patients (p=0.017). The frequency of the CT genotype was significantly higher in colon cancer patients than in control individuals (58.3% vs. 44.8%, Bonferroni corrected p-value=0.024; OR=1.74; 95% CI=1.15-2.62), and in rectal cancer patients (58.3% vs. 28.0%, Bonferroni corrected p-value=0.012; OR=3.59; 95% CI=1.42-9.04). Characteristics of the patients including age, sex, tumor grade and stage were not associated with the PD-1.5 polymorphism. Our results show a significant association between PD-1.5 polymorphism and colon cancer. Larger numbers of patients are required to investigate comprehensively the association of rectal cancer with PD-1.5 polymorphism.