Association between LMP2/LMP7 genetic variability and the metastasis risk of ovarian cancer in Chinese women in Beijing

Integrated genomic analysis of proteasome alterations across 11,057 patients with 33 cancer types: clinically relevant outcomes in framework of 3P medicine

Relevance

Proteasome, a cylindrical complex containing 19S regulatory particle lid, 19S regulatory particle base, and 20S core particle, acted as a major mechanism to regulate the levels of intracellular proteins and degrade misfolded proteins, which involved in many cellular processes, and played important roles in cancer biological processes. Elucidation of proteasome alterations across multiple cancer types will directly contribute to cancer medical services in the context of predictive, preventive, and personalized medicine (PPPM / 3P medicine).

Purpose

This study aimed to investigate proteasome gene alterations across 33 cancer types for discovery of effective biomarkers and therapeutic targets in the framework of PPPM practice in cancers.

Methods

Proteasome gene data, including gene expression RNAseq, somatic mutation, tumor mutation burden (TMB), copy number variant (CNV), microsatellite instability (MSI) score, clinical characteristics, immune phenotype, 22 immune cells, cancer stemness index, drug sensitivity, and related pathways, were systematically analyzed with publically available database and bioinformatics across 11,057 patients with 33 cancer types.

Results

Differentially expressed proteasome genes were extensively found between tumor and control tissues. PSMB4 occurred the top mutation event among proteasome genes, and those proteasome genes were significantly associated with TMB and MSI score. Most of proteasome genes were positively related to CNV among single deletion, control copy number, and single gain. Kaplan-Meier curves and COX regression survival analysis showed proteasome genes were significantly associated with patient survival rate across 33 cancer types. Furthermore, the expressions of proteasome genes were significantly different among different clinical stages and immune subtypes. The expressions of proteasome genes were correlated with immune-related scores (ImmuneScore, StromalScore, and ESTIMATEScore), 22 immune cells, and cancer stemness. The sensitivities of multiple drugs were closely related to proteasome gene expressions. The identified proteasome and proteasome-interacted proteins were significantly enriched in various cancer-related pathways.

Conclusions

This study provided the first landscape of proteasome alterations across 11,057 patients with 33 cancer types and revealed that proteasome played a significant and wide functional role in cancer biological processes. These findings are the precious scientific data to reveal the common and specific alterations of proteasome genes among 33 cancer types, which benefits the research and practice of PPPM in cancers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-021-00256-z.

Genetic polymorphisms of proteasome subunit genes of the MHC-I antigen-presenting system are associated with cervical cancer in a Chinese Han population

Proteasome subunit beta types 8 and 9 (PSMB8, PSMB9) play critical roles in the human leukocyte antigen class I (HLA I)-presenting system. Studies have suggested that polymorphisms in the PSMB8 and PSMB9 genes may influence the immune functions of PSMB8 and PSMB9, and thus be associated with various human cancers. We investigated associations involving single nucleotide polymorphisms (SNPs) rs2071543 in PSMB8, rs1351383, rs17587 and rs2127675 in PSMB9 and risk of cervical intraepithelial neoplasia (CIN) and cervical cancer in a Chinese Han population. A total of 543 patients with CIN, 1008 patients with cervical cancer, and 1120 healthy individuals were enrolled. Agena MassArray was used for SNP genotyping of PSMB8 and PSMB9. Associations involving these SNPs and risk of CIN and cervical cancer were analysed. Our results showed that the PSMB8 T/T and T/G genotypes of rs2071543 may be associated with a higher risk of CIN (P = 0.011, OR = 1.35,95% CI: 1.07-1.70) and cervical cancer (P = 0.006, OR = 1.31, 95% CI: 1.08-1.59). For rs17587, the A allele (P = 0.001, OR = 1.303, 95% CI: 1.115-1.522), and the A/A and A/G genotypes (P = 0.001, OR = 1.36, 95% CI: 1.13-1.63) may be risk factors for cervical cancer. These results indicated that PSMB8 rs2071543 might influence susceptibility to CIN and cervical cancer, and PSMB9 rs17587 might influence cervical cancer susceptibility in a Chinese Han population.

Antigen-adjuvant effects of icariin in enhancing tumor-specific immunity in mastocytoma-bearing DBA/2J mice

Cancer immunotherapy has attracted much attention in recent years because of the ability of immune system to identify tumor cells and limit their growth. Icariin (ICA) is a natural flavonoid glucoside isolated from Epimedium plants and has shown a variety of pharmacological activities such as anti-inflammatory effects, immunological regulation and anticancer potency. Furthermore, it has immunoadjuvant effects on enhancing Th1-immune response, suggesting that ICA may serve as an adjuvant for cancer immunotherapy. In this study, we used P815 mouse mastocytoma tumor model and immunized them with P815AB peptide and/or ICA. Our results demonstrated that ICA could increase the cytotoxic T lymphocytes (CTL) response for P815AB peptide on the tumor-bearing DBA/2J mice. In addition, the percentage of CD4⁺CD8⁺/CD3⁺CD69⁺/CD69⁺NKG2D⁺ positive cells in splenocytes of the tumor-bearing mice all significantly increased after combined immunization with ICA and P815AB peptide. This illustrated that ICA could enhance the immunogenicity of P815AB and improve the ability of T cells and CTLs in recognizing the tumor cells. Moreover, ICA improved the function of peritoneal macrophages with effects of inhibition on tumor growth. Besides, we discussed the possible mechanism of ICA to enhance body immunity by detecting the expression level of MHC-I and related genes in B16-F10 and RMA/S cells. The results suggested that ICA has the potential to up-regulate LMP/TAP related molecules and induce the expression of MHC-I, which increase the immune surveillance and keep cancer in remission. In conclusion, ICA showed an anti-tumor effect both in vitro and in vivo and may be an effective antigen adjuvant for cancer treatment by enhancing tumor-specific immunity.

Impact of LMP7 (rs2071543) gene polymorphism in increasing cancer risk: evidence from a meta-analysis and trial sequential analysis

Genetic variant LMP7 (low molecular weight polypeptide 7) –145 C > A may influence the function of immune surveillance of an individual and lead to cancer development. Various studies have investigated the relevance of LMP7 –145 C > A gene polymorphism with cancer risk; but, their results are conflicting and inconsistent. To obtain a comprehensive conclusion, a meta-analysis was performed by including eight eligible published studies retrieved from PubMed (Medline), EMBASE and Google Scholar web search until December 2016. Individuals with AA genotype (AA vs CC: p = 0.001; OR = 2.602, 95% CI = 1.780 to 3.803) of LMP7 -145 C > A were found to have 2 folds higher risk of cancer than those with CC genotype. The recessive genetic model (AA vs AC + CC) also indicated that individuals with AA genotype have 2 folds higher cancer risk than AC and CC genotypes (p = 0.001; OR = 2.216, 95% CI = 1.525 to 3.221). Also, significant increased cancer risk was observed in Asians but not in Caucasians. No publication bias was observed during the analysis. Trial sequential analysis also strengthened our current findings. These results suggest that genetic variant LMP7–145 C > A has significant role in increasing cancer risk in overall and Asian population, and could be useful as a prognostic marker for early cancer predisposition.

Genetic variability in LMP2 and LMP7 is associated with the risk of esophageal squamous cell carcinoma in the Kazakh population but is not associated with HPV infection

The Kazakh population in Xinjiang Province in northwestern China exhibits a high incidence of esophageal squamous cell carcinoma (ESCC). Although the etiology of esophageal carcinoma (EC) has not been elucidated, there are reports of the involvement of an immunologic mechanism. In the current study, 268 Kazakh ESCC patients and 500 age- and sex-matched control subjects were recruited. DNA was extracted from paraffin-embedded tumor specimens from the patients and peripheral blood lymphocytes from the controls and used for LMP2/LMP7 genotyping. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect LMP2/LMP7 gene single-nucleotide polymorphisms (SNPs). We found a clear increased risk of ESCC in the Kazakh population for the heterozygous LMP2 R/C genotype and the homozygous C/C genotype (OR = 1.470, 95%CI = 1.076–2.008, p = 0.015 forLMP2R/C; OR = 2.048, 95% CI = 1.168–3.591, p = 0.011 for LMP2 C/C). Conversely, the heterozygous LMP7 Q/K polymorphism was found to decrease the risk of ESCC in this population (OR = 0.421, 95% CI = 0.286–0.621, p = 8.83×10⁻⁶). Moreover, LMP2 R/C+C/C genotype was associated with increased tumor invasion depth (p = 0.041). Haplotype analysis showed that haplotype A, which includes wild-type homozygous LMP2/TAP1 and mutant LMP7, decreases susceptibility to ESCC in the Kazakh population; in contrast, haplotype E, which includes wild-type homozygous LMP2/LMP7/TAP1, acts as a risk factor for increased susceptibility to ESCC. This is the first study to report that the heterozygous LMP2 R/C and homozygous C/C genotypes increase susceptibility to ESCC in the Kazakh population and that the heterozygous LMP7 Q/K genotype decreases susceptibility to ESCC in this population. Nevertheless, neither LMP2 nor LMP7 was associated with human papillomavirus (HPV) infection. Understanding LMP2/LMP7 genetic variability will provide a new therapeutic perspective for Kazakh patients with ESCC.

Association between LMP2/LMP7 genetic variability and cancer susceptibility, especially among Asians: evidence from a meta-analysis

Low molecular mass protein (LMP) gene performs a critical role in the foreign antigen processing machine via the major histocompatibility complex-I (MHC-I) complex CD8+ cytotoxic T lymphocytes (CTL) pathway. Recent studies have reported the association of LMP2-60 G>A (rs17587) and LMP7-145 C>A (rs2071543) polymorphisms with various types of cancers, but the outcomes remained inconsistent. To obtain a reliable conclusion, we summarized available data and conducted a meta-analysis involving a total of 19 published studies. Evidences were obtained from the PubMed, Google Scholar, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases. The results demonstrated that the rs17587 and rs2071543 polymorphisms were associated with an increased cancer risk in the recessive and homozygote models. Stratified analyses by ethnicity indicated a significant association only in Asian population. Furthermore, rs17587 showed a greater susceptibility to gynecological cancers, while rs2071543 increased the risk of gastrointestinal and gynecological cancers. Our results indicate that the LMP2 rs17587 and LMP7 rs2071543 polymorphisms may act as risk factors for cancer, especially for Asian populations. Additional larger-scale multicenter studies should be performed to validate our results.

Three Gene Signature for Predicting the Development of Hepatocellular Carcinoma in Chronically Infected Hepatitis C Virus Patients

Hepatitis C virus (HCV) is the leading cause of liver fibrosis and hepatocellular carcinoma (HCC). At present, there is no predictive biomarker for the patients at high risk of developing HCC. In this study, we examined the association between single-nucleotide polymorphisms (SNPs) in 3 innate immunity genes [2'-5'oligoadenylate synthetase 1 (OAS1) rs10774671, interleukin 28B (IL28B) rs12979860, and low molecular mass polypeptide 7 (LMP-7) at codon 49] besides cytomegalovirus (CMV) coinfection and susceptibility to HCC in genotype 4 (GT4) chronically infected Egyptian patients. SNPs were determined using restriction fragment length polymorphism analysis in DNA from HCC patients (n = 34) and compared with either controls (n = 70) or patients with early grades of liver fibrosis (n = 49). Our results demonstrated that patients bearing the genetic combination consisting of LMP-7 CA/AA [OR 4.75, 95% confidence interval (CI) 1.443-15.631, P = 0.007] and IL28B rs12979860 CT/TT (OR 6.00, 95% CI 1.603-22.455, P = 0.004) and positive for CMV viremia (OR 3.11, 95% CI 1.151-8.412, P = 0.02) were more likely to have HCC. However, OAS1 rs10774671 does not seem to contribute to the development of HCC. Binary regression analysis indicated that HCC risk significantly increases with the presence of each unfavorable genotype (LMP-7 CA/AA, IL28B rs12979860 CT/TT), when accompanied by the existence of CMV coinfection (probability of HCC risk is 0.8 for combined factors versus 0.14, 0.07, and 0.07 for individual factor IL28B, LMP-7, and CMV; respectively). These data suggest that the 2 SNPs and the coinfection in concert have potential in predicting the risk of HCC development in patients infected with HCV GT4.

MiR-451 suppresses cell proliferation and metastasis in A549 lung cancer cells

Recent study showed that inflammation was related to lung cancer. However, the exact cause of lung inflammation leading to carcinogenesis is unknown. MicroRNAs (miRNAs) are a group of endogenous non-coding small RNAs that regulate the activity of targeted mRNAs by inflammatory response in many diseases. MiR-451 was reported to relate to the development of lung cancer and metastasis of glioma. But the effect of miR-451 on cell proliferation, migration, and invasion of lung cancer is not really clear. In order to explore the molecular mechanism of the occurrence and development of lung cancer, we investigated the effect of human miR-451 on the proliferation, invasion, and metastasis in lung cancer cell line A549. The miR-451 expression construct was generated into pGenesil-1.1 and transfected into A549 cells. Results showed that the recombinant vectors were verified by sequencing. And miR-451 was over-expressed in A549 by real-time RT PCR. Furthermore, the proliferation, invasion, and metastasis of the cells in miR-451 group were inhibited significantly compared with those in control and A549 groups by MTT assay, Transwell invasion assay, and wound-healing assay. And the lung cancer metastasis factors (MMP-2, MMP-9, VEGF, and CXCR4) were decreased in miR-451 group by Western blot. Moreover, it was proved that inflammation-related gene-PSMB8 was a target for miR-451 by bioinformatics analysis and dual-luciferase reporter assay. And the protein expressions of PSMB8 and NOS2 were decreased in miR-451 group compared with those in control and A549 groups. Therefore, our findings indicated that miR-451 related to PSMB8/NOS2 inflammatory factors may suppress the development and migration of lung cancer, providing evidence for the role of miR-451 in lung cancer.

Association between LMP2 and LMP7 gene polymorphisms and the risk of gastric cancer: A case-control study

The integrality of low molecular weight protein (LMP)2/LMP7 function plays an important role in the processing of GC cell antigens. The purpose of the present hospital-based case-control study was to estimate the effect of polymorphisms in the LMP2 and LMP7 genes on the risk of GC. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to distinguish the Arg to His substitution at codon 60 of LMP2 (LMP2-60) and the Gln to Lys substitution at codon 145 of LMP7 (LMP7-145) in 502 gastric cancer patients and 502 age and gender-matched cancer-free control individuals. The Lys allele of the LMP7-145 variant was more frequent in GC patients compared with control individuals [P=0.004; adjusted odds ratio (OR), 1.39; 95% confidence interval (CI), 1.11-1.74]. The Gln/Lys and Lys/Lys genotypes increased the risk of GC compared with the Gln/Gln genotype (P=0.049 and P=0.041, respectively; adjusted OR, 1.32 and 2.13, respectively; 95% CI, 1.00-1.73 and 1.03-4.39, respectively). Compared with the Gln/Gln genotype, the LMP7-145 Gln/Lys and Lys/Lys variants of the LMP7 gene were also associated with increased susceptibility to GC (P=0.017; adjusted OR, 1.38; 95% CI, 1.06-1.80). Haplotype analysis revealed that the LMP2 (Arg)-LMP7 (Lys) haplotype was associated with increased risk of GC (P=0.013, adjusted OR=1.34, 95% CI=1.06-1.70). Stratified analysis revealed that the association between the risk of GC and the variant genotypes of LMP7-145 was stronger in older individuals (>59 years), males and non-smokers. However, no association between the LMP2-60 polymorphism and the risk of GC was observed. The present results suggest that the LMP7-145 genetic variant contributes to increased susceptibility to GC, and the Lys allele is an independent risk factor for GC.