PD-L1 gene copy number and promoter polymorphisms regulate PD-L1 expression in tumor cells of non-small cell lung cancer patients

CircITSN2-miR-17-5p/20a-5p/20b-5p-PD-L1 regulatory network is a potential molecular mechanism of PD-L1 gene involving in immune response to IBDV

AbstractImmunosuppression induced by infectious bursal disease virus (IBDV) and its subsequent secondary infections remain the serious problems that urgently need to be addressed in poultry industry. Even more troubling, the molecular mechanism of IBDV-induced immunosuppression is not fully understood. In this study, expression characteristics of immune checkpoint programmed cell death-ligand 1 (PD-L1) gene were explored in chicken immune response induced by IBDV attenuated vaccine, and the competing endogenous RNA (ceRNA) regulatory mechanism of PD-L1 gene in vivo was identified by quantitative real-time PCR (qRT-PCR). The results showed that PD-L1 gene expressions were closely related to the immune response to IBDV, and played important regulatory roles in the immune-related tissues at different stages of the immune response. Significant game relationships in expression levels between miR-17 family members (miR-17-5p, miR-20a-5p, and miR-20b-5p), circITSN2, and PD-L1 gene were identified in vivo, so the circITSN2-miR-17-5p/20a-5p/20b-5p-PD-L1 network was a potential molecular regulatory mechanism of PD-L1 in the immune response to IBDV vaccine, and heart (5 dpi), proventriculus (5 dpi), and lung (21 dpi) were the key tissues. This study can provide valuable references for further studying the molecular mechanisms of immunosuppression induced by IBDV.

Polymorphisms of the PD-L1 gene 3'-untranslated region are associated with the expression of PD-L1 in non-small cell lung cancer

Recent results show that polymorphisms of programmed death ligand 1 (PD-L1, also known as CD274 or B7-H1) might be used as a possible marker for effectiveness of chemotherapy and cancer risk. However, the effect of PD-L1 gene variations on PD-L1 expression remain unclear. Given the post-transcriptional machinery in tumor PD-L1 expression, we investigated single nucleotide polymorphisms (SNPs) in the 3'-untranslated region (3'-UTR) of the PD-L1 gene, rs4143815 and rs4742098, using formalin-fixed paraffin-embedded sections of 154 patients with non-small cell lung cancers (NSCLCs). In rs4143815, the GG genotype showed significant association with PD-L1 expression (P = 0.032). In rs4742098, the AA genotype was significantly associated with histology and PD-L1 expression (P = 0.022 and P = 0.008, respectively). In multivariate logistic regression analysis, the AA genotype in rs4742098 was correlated with PD-L1 expression (odds ratio 0.408, P = 0.048). Interestingly, approximately 10% of the NSCLC cases showed somatic mutation when we compared genotypes of these SNPs between NSCLC tissues and non-tumor tissues from the same patients. In addition, cases with somatic mutation showed higher levels of PD-L1 expression than cases with germline mutation in rs4143815 GG. In conclusion, we demonstrated that the rs4143815 and rs4742098 SNPs in the 3'-UTR of PD-L1 were associated with tumor PD-L1 expression in NSCLCs.

The blockage signal for PD-L1/CD274 gene variants and their potential impact on lung carcinoma susceptibility

BACKGROUND

The programmed death-ligand 1 (PD-L1/CD274) gene plays a key function in suppressing anti-tumor immunity through binding to its receptor PD-1 on stimulated T lymphocytes. However, robust associations among diverse populations and lung susceptibility remain unclear. The tentative purpose of this research is to investigate whether PD-L1/CD274 polymorphisms modulate susceptibility to lung carcinoma using totalitarian techniques, including genetic analysis, and sophisticated bioinformatic methods.

METHODS

PD-L1/CD274 (rs822336, rs2297136, and rs4143815) variants were genotyped in 126 lung carcinoma cases and 117 healthy controls using tetra-primer ARMS-PCR. Logistic regression and bioinformatics analyses assessed genetic associations.

RESULTS

The rs2297136 GA genotype significantly increased lung cancer risk by 3.7-fold versus GG genotype (OR 3.69, 95 % CI 1.39-9.81, p = 0.016), with the minor A allele also increasing risk (OR 1.47, p = 0.044). In contrast, the rs4143815 CC genotype was associated with 70 % decreased cancer risk versus GG (OR 0.30, 95 % CI 0.11-0.87, p = 0.012), although the minor C allele itself was not significant. The rs822336 variant showed no association. Haplotype and multivariate analyses supported these findings. In silico predictions suggested functional impacts on PD-L1 expression and activity.

CONCLUSIONS

This study identified novel associations between PD-L1/CD274 polymorphisms and susceptibility to lung cancer in Egyptians. The rs2297136 variant increased risk while the rs4143815 variant conferred protection, highlighting the PD-1/PD-L1 axis as a potential biomarker and therapeutic target in lung oncogenesis. Replication in larger cohorts and functional studies are warranted.

Common inherited variants of PDCD1, CD274 and HAVCR2 genes differentially modulate the risk and prognosis of adenocarcinoma and squamous cell carcinoma

BACKGROUND

To investigate the association between single nucleotide polymorphisms (SNPs) of PDCD1, CD274, and HAVCR2 genes with the risk and outcomes of non-small cell lung cancer (NSCLC) subtypes: squamous cell lung cancer (LUSC) and lung adenocarcinoma (LUAD).

METHODS

TaqMan SNP genotyping assays or polymerase chain reaction-restriction fragment length polymorphism methods were used to determine genotypes of: PDCD1: rs36084323, rs7421861, rs11568821, rs2227981, rs10204525; CD274: rs822335, rs10815225, rs17718883, rs2297136, rs4742098, rs4143815; HAVCR2: rs10057302, rs1036199. Among 383 NSCLC patients, 112 were diagnosed with LUAD and 116 with LUSC. The control group consisted of 433 unrelated, cancer-free subjects.

RESULTS

A CC genotype of rs4143815 and GG genotype of rs4742098 were associated with two times higher risk of developing LUSC (CC vs. GG + GC, OR = 2.31; 95% CI = 1.32, 4.06; P = 0.003; GG vs. AA + AG, OR = 2.26; 95% CI = 1.17, 4.36; P = 0.016, respectively). Moreover, rs4143815 was an independent predictor of the age at diagnosis of LUAD. The carriers of C allele were diagnosed 4.81 years later (95% CI = 1.47, 8.15; P = 0.006) than patients with the GG genotype. The rs10057302 CA genotype was an independent predictor of overall survival in LUSC (adjusted HR = 0.13; 95% CI = 0.02, 0.93; P = 0.043). NSCLC carriers of rs11568821 T allele had almost double the risk of death (adjusted HR = 2.05; 95% CI = 1.28, 3.29; P = 0.003) compared to carriers of CC genotype.

CONCLUSIONS

Our results provided additional evidence that SNPs of genes for PD-1, PD-L1 and TIM-3 differentially modulate the risk and prognosis of LUSC and LUAD.

PD-L1 rs2890658 Polymorphism Increases Risk for Non-Small-Cell Lung Cancer in Northern China Population Based on Experimental Data and Meta-Analysis

Purpose

To dig the PD-L1 rs2890658 polymorphism with susceptibility of non-small-cell lung cancer (NSCLC) in northern China.

Patients and Methods

There were 600 NSCLC patients and 600 age and sex matched controls from the same ethnic origin recruited in the present research. Polymerase chain reaction-restriction fragment length polymorphism method genotyped PD-L1 rs2890658 polymorphism. PubMed and Embase were searched to get eligible literature for meta-analysis. The association between PD-L1 rs2890658 polymorphism and NSCLC risk was calculated with odds ratio and 95% confidence interval.

Results

It is more likely that individuals who have CC genotype and C allele are 2.15 and 1.41 times to develop NSCLC compared with individuals with AA genotype and A allele, respectively. Meta-analysis showed that the individuals who have C allele and CA genotype increased the risk of suffering from NSCLC.

Conclusion

PD-L1 rs2890658 polymorphism increased NSCLC risk in northern China population and it might predict the occurrence of NSCLC.

Association of PD-1 and PDL-1 gene polymorphisms with colorectal cancer risk and prognosis

BACKGROUND

Programmed Cell Death-1 (PD-1) together with Programmed Death Ligand 1 (PDL-1) have crucial roles in anti-tumor immune response, cancer susceptibility and prognosis. Since PD-1 and PDL-1 have been considered as important genetic risk factors in cancer development and their functions can be affected by polymorphic sites, we investigated the effects of PD-1 rs2227981, rs2227982, rs36084323 and PDL-1 rs2282055, rs822336 gene polymorphisms on colorectal cancer (CRC) risk and prognosis in Turkish subjects.

METHODS AND RESULTS

Our study group consisted of 5-FU or Capacitabine prescribed CRC diagnosed patients and healthy controls. Genotype analyses of PD1 and PDL-1 polymorphisms were performed with Agena MassARRAY platform. rs36084323 CT genotype frequency was found to be higher in controls compared to cases (p < 0.001). rs36084323 CT genotype was highly associated with reduced CRC risk compared to CC genotype (OR 0.068, 95% CI 0.022-0.211, p < 0.001). In adjusted analysis, rs2282055 GG genotype was found to be associated with reduced CRC risk (OR 0.271, 95% CI 0.078-0.940, p = 0.040). rs2282055 TT genotype was found to be related to longer progression-free (Bonferroni corrected Log rank p = 0.013) and overall survival (Bonferroni corrected Log rank p = 0.009) to that of GG genotypes. Patients with rs822336 GC+CC genotypes showed longer overall survival times compared to GG (Log rank p = 0.044).

CONCLUSIONS

According to our results, PD-1 rs822336 G > C polymorphism might be useful in predicting CRC prognosis. PDL-1 rs2282055 T > G polymorphism might be useful in predicting both CRC risk and prognosis. Further studies should be conducted in larger and different populations to clear the roles of PD-1 and PDL-1 polymorphisms in CRC risk and prognosis.

PD-1/PD-L1 blockade: Prospectives for immunotherapy in cancer and autoimmunity

Immune checkpoint blockade therapy (ICBT) has become a successful cancer treatment approach in the field of cancer immunotherapy. Blockade of programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) with monoclonal antibodies have been known as successful examples of cancer immunotherapy in recent years. Although ICBT has been shown to be beneficial in cancers, such benefits have only been seen in a portion of cancer patients. In this regard, enhancing the therapeutic effects of inhibiting PD-1 and PD-L1 and reducing the side effects of this approach can be considered as a potential approach in a successful ICBT. In this review, we have highlighted new viewpoints regarding improving the therapeutic effect of PD-1 and PD-L1 blockades in cancer therapy. Besides, their expression levels as a biomarker with prognostic value, their role in intestinal microbiota modulation, combination therapy, and immune-related side effects (irAEs) have been discussed.

Harnessing the epigenome to boost immunotherapy response in non-small cell lung cancer patients

The introduction of immune checkpoint inhibitor (ICI)-based therapy for non-oncogene addicted non-small cell lung cancer (NSCLC) has significantly transformed the treatment landscape of the disease. Inhibitors of the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint axis, which were initially considered as a late-line treatment option, gradually became the standard of care as first-line treatment for subgroups of NSCLC patients. However, a significant fraction of patients either fails to respond or progresses after a partial response to ICI treatment. Thus, the identification of mechanisms responsible for innate and acquired resistance to immunotherapy within a rapidly evolving tumor microenvironment (TME) is urgently required, as is the identification of reliable predictive biomarkers beyond PD-L1 expression. The deregulation of the epigenome is a key driver of cancer initiation and progression, and it has also been shown to drive therapeutic resistance. Tumor education of infiltrating myeloid cells towards an immuno-suppressive phenotype as well as induction of T-cell dysfunction in the TME is also driven by epigenome reprogramming. As it stands and, given their dynamic nature, epigenetic changes in cancer and non-cancer cells represent an attractive target to increase immunotherapy activity in NSCLC. Accordingly, clinical trials of combinatorial immuno-epigenetic drug regimens have been associated with tumor response in previously immunotherapy-resistant NSCLC patients irrespective of their PD-L1 status. Moreover, epigenetic signatures might represent valuable theragnostic biomarkers as they can be assayed easily in liquid biopsy and provide multiple layers of information. In this review, we discuss the current knowledge regarding the dysregulated epigenetic mechanisms contributing to immunotherapy resistance in NSCLC. Although the clinical data are still maturing, we highlight the attractive perspective that the synergistic model of immuno-epigenetic strategies might overcome the current limitations of immunotherapy alone and will be translated into durable clinical benefit for a broader NSCLC population.

Impact of copy number variant and single nucleotide polymorphism of the programmed death-ligand 1 gene, programmed death-ligand 1 protein expression and therapy regimens on overall survival in a large group of Caucasian patients with non-small cell lung carcinoma

Anti-programmed death-1 or anti-programmed death-ligand 1 (PD-L1) blockade may be ineffective in some patients with non-small cell lung cancer (NSCLC) with high percentage of tumor cells with PD-L1 expression. In addition, immunotherapy may provide great benefits in patients without PD-L1 expression. The present study assessed PD-L1 protein expression by immunohistochemistry, copy number variation (CNV) of PD-L1 and two single nucleotide polymorphisms (SNPs), rs822335 and rs822336, in the promoter of PD-L1 by quantitative PCR in 673 patients with NSCLC. Overall survival time of patients with NSCLC depending on the assessed predictive factors (PD-L1 CNV or SNP) and the treatment methods (immunotherapy in first/second line of treatment or chemotherapy) was analyzed. The present study revealed significantly higher PD-L1 copies number in patients with ≥10% and ≥50% of tumor cells with PD-L1 expression compared to patients with lower percentage of PD-L1-positive tumor cells (P=0.02 and P=0.0002, respectively). There was a significant positive correlation (R=0.2; P=0.01) between number of PD-L1 copies and percentage of tumor cells with PD-L1 protein expression. Percentage of tumor cells with PD-L1 expression was lower in patients with TT genotype of the rs822335 polymorphism compared to those with CC genotype (P=0.03). The present study observed significantly higher risk of death in patients treated with chemotherapy compared to those treated with immunotherapy (P<0.0001; hazard ratio=2.4768; 95% confidence interval, 2.0120–3.0490). The present study demonstrated a close relationship between PD-L1 copies number, genotype of rs822335 PD-L1 polymorphism and PD-L1 protein expression on tumor cells. However, the impact of CNV and SNPs of PD-L1 on overall survival of patients with NSCLC requires further investigation.

Relevance of PD-L1 Non-Coding Polymorphisms on the Prognosis of a Genetically Admixed NSCLC Cohort

Purpose

Although non-small cell lung cancer (NSCLC) remains a deadly disease, new predictive biomarkers have emerged to assist in managing the disease, of which one of the most promising is the programmed death‐ligand 1 (PD-L1). Each, PD-L1 variant seem to modulate the function of immune checkpoints differently and affect response to adjuvant treatment and outcome in NSCLC patients. We thus investigated the influence of these PD-L1 genetic variations in genetically admixed NSCLC tissue samples, and correlated these values with clinicopathological characteristics, including prognosis.

Materials and Methods

We evaluated PD-L1 non-coding genetic variants and protein expression in lung adenocarcinomas (ADC), squamous cell carcinomas (SqCC), and large cell carcinomas (LCC) in silico. Microarray paraffin blocks from 70 samples of ADC (N=33), SqCC (N=24), and LCC (N=13) were used to create PD-L1 multiplex immunofluorescence assays with a Cell Signaling E1L3N clone. Fifteen polymorphisms of the PD-L1 gene were investigated by targeted sequencing and evaluated in silico using dedicated tools.

Results

Although PD-L1 polymorphisms seemed not to interfere with protein expression, PD-L1 expression varied among different histological subtypes, as did clinical outcomes, with the rs4742098A>G, rs4143815G>C, and rs7041009G>A variants being associated with relapse (P=0.01; P=0.05; P=0.02, respectively). The rs7041009 GG genotype showed a significant correlation with younger and alive patients compared to carriers of the A allele (P=0.02 and P<0.01, respectively). The Cox regression model showed that the rs7041009 GG genotype may influence OS (P<0.01) as a co-dependent factor associated with radiotherapy and recurrence in NSCLC patients. Furthermore, the Kaplan–Meier survival curves showed that rs7041009 and rs4742098 might impact PPS in relapsed patients. In silico approaches identified the variants as benign.

Conclusion

PD-L1 non-coding variants play an important role in modulating immune checkpoint function and may be explored as immunotherapy biomarkers. We highlight the rs7041009 variant, which impacts OS and PPS in NSCLC patients.

Influence of Programmed Death Ligand-1-Gene Polymorphism rs822336 on the Prognosis and Safety of Postoperative Patients with NSCLC Who Received Platinum-Based Adjuvant Chemotherapy

Purpose

This study was done to investigate the influence of PDL1-gene polymorphism on the prognosis and safety of postoperative patients with non–small cell lung cancer (NSCLC) who had received platinum-based adjuvant chemotherapy.

Methods

A total of 289 postoperative patients with NSCLC who had received platinum-based adjuvant chemotherapy from January 2012 to June 2019 participated in this study. Recurrence status and adverse reactions were documented during adjuvant chemotherapy. Overall survival (OS) data were obtained through telephone follow-up. DNA extracted from hematologic specimens was genotyped for PDL1-gene polymorphism. Associations between genotype status and prognosis were assessed using Kaplan–Meier survival analysis, and multivariate adjustment was performed using Cox regression analysis.

Results

Median disease-free survival of the 289 patients with NSCLC was 3.3 years and median OS 4.9 years. With regard to the PDL1 gene polymorphism, only rs822336 was of clinical significance in the subsequent analysis. The minor-allele frequency of rs822336 was 0.21, and distribution of the three genotypes was in accordance with the Hardy–Weinberg equilibrium (P=0.807). Survival analysis according to genotype status suggested that median disease-free survival of patients with GG and GC/CC genotypes was 2.8 and 4.1 years, respectively (P=0.01). Median OS of patients with GG and GC/CC genotypes was 4.1 and 5.4 years, respectively (P=0.008). However, the safety analysis failed to find a significant association between the polymorphism and adverse reactions. Interestingly, expression analysis of RNA extracted from peripheral blood mononuclear cells indicated that PDL1-mRNA expression of patients with the GG genotype was significantly higher than for the GC/CC genotype (P<0.001).

Conclusion

The prognosis of postoperative patients with NSCLC who have received platinum-based adjuvant chemotherapy may be influenced by the rs822336 polymorphism through mediation of the mRNA expression of PDL1.

The influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer patients received capecitabine-based adjuvant chemotherapy: a long-term follow-up, real-world retrospective study

PURPOSE

This study investigated the influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer (CRC) patients who received capecitabine-based adjuvant chemotherapy in real world.

METHODS

A total of 315 CRC patients underwent R0 surgical resection and received capecitabine-based adjuvant chemotherapy were included. Clinical characteristics were collected from the hospital record system, prognosis was obtained by telephone follow-up. Peripheral blood and peripheral blood mononuclear cell (PBMC) specimen of CRC patients were performed for the genotyping of polymorphism and mRNA expression of PD-L1, respectively. Analysis on the association between genotypes and prognosis was conducted.

RESULTS

The median disease-free survival (DFS) of the 315 CRC patients was 5.1 years, the median overall survival (OS) was 6.0 years. Regarding the PD-L1 gene polymorphism analysis, the prevalence of 901T>C among the CRC patients was as follows: TT genotype 221 cases (70.16%), TC genotype 86 cases (27.30%), CC genotype 8 cases (2.54%), the minor allele frequency was 0.16, the distribution of three genotypes was in accordance with Hardy-Weinberg equilibrium (P = 0.915). Moreover, the prognosis analysis indicated that the median DFS of patients with TT and TC/CC genotype was 5.4 and 4.0 years, respectively (P = 0.008). The median OS of patients with the two genotypes was 6.4 and 5.0 years (P = 0.007). The multivariate Cox regression analysis showed that the TC/CC genotypes were an independent factor for DFS (odds ratio = 1.56, P = 0.018). Furthermore, the mRNA expression results indicated that the mRNA expression of PD-L1 in PBMC of the patients with TC/CC genotype was significantly higher than patients with TT genotype (P < 0.001).

CONCLUSION

The prognosis of R0 resection CRC patients received capecitabine-based adjuvant chemotherapy in real world may be influenced by PD-L1 901T>C polymorphism through mediation of the mRNA expression of PD-L1.