Prognostic relevance of genetic variants involved in immune checkpoints in patients with colorectal cancer

Immunotherapy for colorectal cancer: insight from inherited genetics

Immunotherapy shows efficacy for multiple cancer types and potential for expanded use. However, current immune checkpoint inhibitors (ICIs) are ineffective against microsatellite-stable colorectal cancer (CRC), which is more commonly diagnosed. Immunotherapy strategies for non-responsive CRC, including new targets and new combination therapies, are being tested to address this need. Importantly, a subset of inherited germline genetic variants associated with CRC risk are predicted to regulate genes with immune functions, including genes related to existing ICIs, as well as new potential targets in the major histocompatibility complex (MHC) region and immunoregulatory cytokines. We review discoveries in the inherited genetics of CRC related to the immune system and draw connections with ongoing developments and emerging immunotherapy targets.

Associations between Single Nucleotide Polymorphisms from the Genes of Chemokines and the CXCR2 Chemokine Receptor and an Increased Risk of Endometrial Cancer

Significant relationships with endometrial cancer were demonstrated, both for CCL2, CCL5, and CXCL8 chemokines and for the chemokine receptor CXCR2. The reported case-control study of genetic associations was designed to establish the role of selected single nucleotide polymorphisms (SNPs) of the CCL2, CCL5, CXCL8, and CXCR2 genes in the onset and progression of endometrial cancer. This study was conducted on 282 women, including 132 (46.8%) patients with endometrial cancer and 150 (53.2%) non-cancerous controls. The genotypes for CCL2 rs4586, CCL5 rs2107538 and rs2280789, CXCL8 rs2227532 and -738 T>A, and CXCR2 rs1126580 were determined, using PCR-RFLP assays. The AA homozygotes in CCL5 rs2107538 were associated with more than a quadruple risk of endometrial cancer (p ≤ 0.050). The GA heterozygotes in the CXCR2 SNP were associated with approximately threefold higher cancer risk (p ≤ 0.001). That association also remained significant after certain adjustments, carried out for age, diabetes mellitus, arterial hypertension, or endometrial thickness above 5 mm (p ≤ 0.050). The A-A haplotypes for the CCL5 polymorphisms and T-A-A haplotypes for the CCL2 and CCL5 SNPs were associated with about a twofold risk of endometrial cancer (p ≤ 0.050). In conclusion, CCL2 rs4586, CCL5 rs2107538 and rs2280789, and CXCR2 rs1126580 demonstrated significant associations with an increased risk of endometrial cancer.

Overview of Research on Germline Genetic Variation in Immune Genes and Cancer Outcomes

Since the late 19th century, the immune system has been known to play a role in cancer risk, initiation, and progression. Genome-wide association studies (GWAS) have identified hundreds of genetic risk loci for autoimmune and inflammatory diseases, yet the connection between human genetic variation and immune-mediated response to cancer treatments remains less well-explored. Understanding inherited genetic variation, with respect to germline genetic polymorphisms that affect immune system pathways, could lead to greater insights about how these processes may best be harnessed to successfully treat cancer. Our goal in this manuscript was to understand progress and challenges in assessing the role of inherited genetic variation in response to cancer treatments. Overall, the 39 studies reviewed here suggest that germline genetic variation in immune system related genes may potentially affect responses to cancer treatments. Although further research is needed, considering information on germline immune genetic variation may help, in some cases, to optimize cancer treatment.

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.

Oncolytic herpes simplex virus HF10 (canerpaturev) promotes accumulation of CD8+ PD-1- tumor-infiltrating T cells in PD-L1-enriched tumor microenvironment

Oncolytic viruses (OVs) remodel the tumor microenvironment by switching a "cold" tumor into a "hot" tumor with high CD8⁺ T-cell infiltration. CD8⁺ T-cell activity plays an essential role in the antitumor efficacy of OVs. However, the activity of T cells is impaired by the programmed cell death protein-1/programmed cell death-ligand 1 (PD-1/PD-L1) interaction. To date, it remains unclear why OVs alone have a significant antitumor activity even when PD-L1 expression persists on tumor or immune cells. In this study, we found that canerpaturev (C-REV) treatment significantly suppressed tumor growth, even though it induced a significant increase in PD-L1 expression in tumors in vivo as well as persistence of high PD-L1 expression on antigen-presenting cells (macrophage and dendritic cells [DCs]). Surprisingly, we observed that C-REV treatment increased the abundance of activated CD8⁺ PD-1^- tumor-infiltrating lymphocytes (TILs) in the tumor on both the injected and contralateral sides, although infiltration of CD8⁺ PD-1^high TILs into the tumor was observed in the control group. Moreover, the difference in PD-1 expression was observed only in tumors after treatment with C-REV, whereas most CD8⁺ T cells in the spleen, tumor-draining lymph nodes and blood were PD-1-negative, and this did not change after C-REV treatment. In addition, changes in expression of T-cell immunoglobulin and mucin-domain containing-3 and T-cell immune-receptor with Ig and ITIM domains were not observed on CD8⁺ TILs after C-REV treatment. Taken together, our findings may reveal mechanisms that allow OVs to trigger an antitumor immune response, irrespective of a PD-L1-enriched tumor microenvironment, by recruitment of CD8⁺ PD-1^- TILs.

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.

Hyperprogression under Immune Checkpoint Inhibitor: a potential role for germinal immunogenetics

Hyperprogressive disease (HPD), an unexpected acceleration of tumor growth kinetics, is described in cancer patients treated with anti-PD-1/anti-PD-L1 agents. Here, our aim was to take into consideration the host and explore whether single nucleotide polymorphisms (SNPs) in key genes involved in immune response might predispose to HPD. DNA was extracted from blood-samples from 98 patients treated under CPI monotherapy. Four candidate genes (PD-1, PD-L1, IDO1 and VEGFR2) and 15 potential SNPs were selected. The TGK_R (ratio of the slope of tumor growth before treatment and the slope of tumor growth on treatment) was calculated. Hyperprogression was defined as a TGK_R≥2. TGK_R calculation was feasible for 80 patients (82%). HPD was observed for 11 patients (14%) and was associated with shorter overall survival (P = 0.003). In univariate analysis, HPD was significantly associated with age ≥70 y (P = 0.025), immune-related toxicity (P = 0.016), VEGFR2 rs1870377 A/T or A/A (P = 0.005), PD-L1 rs2282055 G/T or G/G (P = 0.024) and PD-L1 rs2227981 G/A or A/A (P = 0.024). Multivariate analysis confirmed the correlation between HPD and age ≥70 y (P = 0.006), VEGFR2 rs1870377 A/T or A/A (P = 0.007) and PD-L1 rs2282055 G/T or G/G (P = 0.018). Immunogenetics could become integral predictive factors for CPI-based immunotherapy.

Prognostic Value of Lymphocyte-Activation Gene 3 (LAG3) in Cancer: A Meta-Analysis

Introduction: Therapeutic targeting of inhibitors of the immune response has reached the clinical setting. Inhibitors of the novel receptor LAG3, which negatively regulates T-cell activation, are under investigation. Here we explore the presence and prognostic role of LAG3 in cancer.

Methods: A systematic search of electronic databases identified publications exploring the effect of LAG3 on overall survival (OS) and (for early-stage cancers) disease-free survival (DFS). Hazard ratios (HR) were pooled in a meta-analysis using generic inverse-variance and random effect modeling. Subgroup analyses were conducted based on disease site and tumor type.

Results: Fifteen studies met the inclusion criteria. LAG3 was associated with better overall survival [HR 0.81, 95% confidence interval (CI) 0.66–0.99; P = 0.04], with subgroup analysis showing no significant differences between disease-site subgroups. The beneficial effect of LAG3 on OS was of greater magnitude in early-stage malignancies (HR 0.73, 95% CI 0.60–0.88) than in the metastatic setting (HR 1.20, 95% CI 0.70–2.05), but this difference was not statistically significant (subgroup difference p = 0.18). LAG3 did not have a significant association with DFS [HR 1.02, 95% confidence interval (CI) 0.77–1.37; P = 0.87], with subgroup analysis showing worse DFS in patients with lymphoma and improved DFS in those with breast cancer.

Conclusions: High expression of LAG3 is associated with favorable overall survival in several solid tumors. A trend toward an association in early-stage disease suggests the importance of immune surveillance in this setting.

Polymorphism of the programmed death-ligand 1 gene is associated with its protein expression and prognosis in gastric cancer

BACKGROUND AND AIM

While the incidence and mortality of gastric cancer (GC) remains high, and prognosis of GC remains poor, molecules in programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and programmed death-ligand 2 (PD-L2) pathway are promising prognostic biomarker of GC. The polymorphisms on PD-1, PD-L1, and PD-L2 may be associated with their protein expressions and affect the survival of GC patient.

METHODS

Seven hundred fifty-six GC patients who voluntarily supplied blood samples were enrolled in our study. We genotyped nine polymorphisms on PD-1, PD-L1, and PD-L2, then evaluated the association of the single nucleotide polymorphisms with GC prognosis and analyzed the relationship between the PD-1, PD-L1, and PD-L2 single nucleotide polymorphism genotypes and their protein expression.

RESULTS

We found that PD-L1 rs822336 CC genotype was independently associated with a better survival of all GC patients and those without postoperative chemotherapy (hazard ratio [HR] = 0.504, 95% confidence interval [CI] = 0.283-0.897 and HR = 0.385, 95% CI = 0.189-0.786). AA+AG genotype of rs2297136 in 3'UTR of the PD-L1 was correlated with the protein expression of PD-L1 protein both in patients overall and those without postoperative chemotherapy (P = 0.013 and P = 0.012). AA+AG genotype of rs2297136 served as an independent factor of better prognosis in patients without postoperative chemotherapy (HR = 0.348, 95% CI = 0.125-0.968).

CONCLUSIONS

Overall, PD-L1 polymorphisms and protein expression were associated with the prognosis of patients with GC.

Targeting Protein Kinases to Enhance the Response to anti-PD-1/PD-L1 Immunotherapy

The interaction between programmed cell death protein (PD-1) and its ligand (PD-L1) is one of the main pathways used by some tumors to escape the immune response. In recent years, immunotherapies based on the use of antibodies against PD-1/PD-L1 have been postulated as a great promise for cancer treatment, increasing total survival compared to standard therapy in different tumors. Despite the hopefulness of these results, a significant percentage of patients do not respond to such therapy or will end up evolving toward a progressive disease. Besides their role in PD-L1 expression, altered protein kinases in tumor cells can limit the effectiveness of PD-1/PD-L1 blocking therapies at different levels. In this review, we describe the role of kinases that appear most frequently altered in tumor cells and that can be an impediment for the success of immunotherapies as well as the potential utility of protein kinase inhibitors to enhance the response to such treatments.

Programmed cell death-1 3'-untranslated region polymorphism is associated with spontaneous clearance of hepatitis B virus infection

Hepatitis B virus (HBV)-specific CD8+ T cells play an important role in the clearance of HBV infection. Programmed cell death-1 (PD-1), an immunosuppressive molecule that regulates T-cell activation and peripheral immune tolerance, is increasingly shown to influence the outcome of HBV infection. rs10204525, a single-nucleotide polymorphism in the 3'-untranslated region (3'-UTR) of PD-1, has been associated with susceptibility and disease progression of chronic HBV infection in far-eastern patients. The aim of our study was to assess the impact of rs10204525 variation on HBV infection in Moroccan patients. A total of 236 patients with chronic HBV infection and 134 individuals with spontaneous HBV resolution were genotyped using a Taqman assay. In addition, PD-1 mRNA expression in peripheral blood nuclear cells was determined by quantitative reverse-transcription polymerase chain reaction. We found that the AA genotype is protective (odds ratio, 0.43; 95% confidence interval, 0.19 to 0.97; P = 0.038) against HBV infection. Interestingly, PD-1 messenger RNA (mRNA) expression analysis has revealed that chronic HBV carriers with GG and GA displayed higher levels of PD-1 mRNA compared with corresponding genotypes in resolved subjects (P = 0.031 and 0.014, respectively). Our data suggest that Mediterranean HBV-infected patients carrying PD-1 GG and GA genotypes at rs10204525 have high PD-1 mRNA expression and may be more prone to installation of chronicity.

A Genetic Polymorphism in CTLA-4 Is Associated with Overall Survival in Sunitinib-Treated Patients with Clear Cell Metastatic Renal Cell Carcinoma

Purpose: The survival of patients with clear cell metastatic renal cell carcinoma (cc-mRCC) has improved substantially since the introduction of tyrosine kinase inhibitors (TKI). With the fact that TKIs interact with immune responses, we investigated whether polymorphisms of genes involved in immune checkpoints are related to the clinical outcome of cc-mRCC patients treated with sunitinib as first TKI.Experimental Design: Twenty-seven single-nucleotide polymorphisms (SNP) in CD274 (PD-L1), PDCD1 (PD-1), and CTLA-4 were tested for a possible association with progression-free survival (PFS) and overall survival (OS) in a discovery cohort of 550 sunitinib-treated cc-mRCC patients. SNPs with a significant association (P < 0.05) were tested in an independent validation cohort of 138 sunitinib-treated cc-mRCC patients. Finally, data of the discovery and validation cohort were pooled for meta-analysis.Results:CTLA-4 rs231775 and CD274 rs7866740 showed significant associations with OS in the discovery cohort after correction for age, gender, and Heng prognostic risk group [HR, 0.84; 95% confidence interval (CI), 0.72-0.98; P = 0.028, and HR, 0.73; 95% CI, 0.54-0.99; P = 0.047, respectively]. In the validation cohort, the associations of both SNPs with OS did not meet the significance threshold of P < 0.05. After meta-analysis, CTLA-4 rs231775 showed a significant association with OS (HR, 0.83; 95% CI, 0.72-0.95; P = 0.008). Patients with the GG genotype had longer OS (35.1 months) compared with patients with an AG (30.3 months) or AA genotype (24.3 months). No significant associations with PFS were found.Conclusions: The G-allele of rs231775 in the CTLA-4 gene is associated with an improved OS in sunitinib-treated cc-mRCC patients and could potentially be used as a prognostic biomarker. Clin Cancer Res; 24(10); 2350-6. ©2018 AACR.

Exploiting scavenger receptors in cancer immunotherapy: Lessons from CD5 and SR-B1

Scavenger receptors (SRs) are structurally heterogeneous cell surface receptors characterized by their capacity to remove extraneous or modified self-macromolecules from circulation, thus avoiding the accumulation of noxious agents in the extracellular space. This scavenging activity makes SRs important molecules for host defense and homeostasis. In turn, SRs keep the activation of the steady-state immune response in check, and participate as co-receptors in the priming of the effector immune responses when the macromolecules are associated with a threat that might compromise host homeostasis. Therefore, SRs built up sophisticated sensor mechanisms controlling the immune system, which may be exploited to develop novel drugs for cancer immunotherapy. In this review, we focus on the regulation of the anti-tumor immune response by two paradigmatic SRs: the lymphocyte receptor CD5 and the more broadly distributed scavenger receptor class B type 1 (SR-B1). Cancer immunity can be boosted by blockade of SRs working as immune checkpoint inhibitors (CD5) and/or by proper engagement of SRs working as innate danger receptor (SR-B1). Thus, these receptors illustrate both the complexity of targeting SRs in cancer immunotherapy and also the opportunities offered by such an approach.