Immunological classification of hepatitis B virus-positive hepatocellular carcinoma by transcriptome analysis

BACKGROUND

Hepatitis B virus (HBV) infection is a major factor responsible for HBV+ hepatocellular carcinoma (HCC).

AIM

An immunological classification of HBV+ HCC may provide both biological insights and clinical implications for this disease.

METHODS

Based on the enrichment of 23 immune signatures, we identified two immune-specific subtypes (Imm-H and Imm-L) of HBV+ HCC by unsupervised clustering. We showed that this subtyping method was reproducible and predictable by analyzing three different datasets.

RESULTS

Compared to Imm-L, Imm-H displayed stronger immunity, more stromal components, lower tumor purity, lower stemness and intratumor heterogeneity, lower-level copy number alterations, higher global methylation level, and better overall and disease-free survival prognosis. Besides immune-related pathways, stromal pathways (ECM receptor interaction, focal adhesion, and regulation of actin cytoskeleton) and neuro-related pathways (neuroactive ligand-receptor interaction, and prion diseases) were more highly enriched in Imm-H than in Imm-L. We identified nine proteins differentially expressed between Imm-H and Imm-L, of which MYH11, PDCD4, Dvl3, and Syk were upregulated in Imm-H, while PCNA, Acetyl-a-Tubulin-Lys40, ER-α_pS118, Cyclin E2, and β-Catenin were upregulated in Imm-L.

CONCLUSION

Our data suggest that “hot” tumors have a better prognosis than “cold” tumors in HBV+ HCC and that “hot” tumors respond better to immunotherapy.

Hepatocellular carcinoma (HCC): Epidemiology, etiology and molecular classification

Hepatocellular carcinoma (HCC), the primary malignancy of hepatocytes, is a diagnosis with bleak outcome. According to National Cancer Institute's SEER database, the average five-year survival rate of HCC patients in the US is 19.6% but can be as low as 2.5% for advanced, metastatic disease. When diagnosed at early stages, it is treatable with locoregional treatments including surgical resection, Radio-Frequency Ablation, Trans-Arterial Chemoembolization or liver transplantation. However, HCC is usually diagnosed at advanced stages when the tumor is unresectable, making these treatments ineffective. In such instances, systemic therapy with tyrosine kinase inhibitors (TKIs) becomes the only viable option, even though it benefits only 30% of patients, provides only a modest (~3months) increase in overall survival and causes drug resistance within 6months. HCC, like many other cancers, is highly heterogeneous making a one-size fits all option problematic. The selection of liver transplantation, locoregional treatment, TKIs or immune checkpoint inhibitors as a treatment strategy depends on the disease stage and underlying condition(s). Additionally, patients with similar disease phenotype can have different molecular etiology making treatment responses different. Stratification of patients at the molecular level would facilitate development of the most effective treatment option. With the increase in efficiency and affordability of "omics"-level analysis, considerable effort has been expended in classifying HCC at the molecular, metabolic and immunologic levels. This review examines the results of these efforts and the ways they can be leveraged to develop targeted treatment options for HCC.

Immunological classification of gliomas based on immunogenomic profiling

Background

Gliomas are heterogeneous in the tumor immune microenvironment (TIM). However, a classification of gliomas based on immunogenomic profiling remains lacking.

Methods

We hierarchically clustered gliomas based on the enrichment levels of 28 immune cells in the TIM in five datasets and obtained three clusters: immunity-high, immunity-medium, and immunity-low.

Results

Glioblastomas were mainly distributed in immunity-high and immunity-medium, while lower-grade gliomas were distributed in all the three subtypes and predominated in immunity-low. Immunity-low displayed a better survival than other subtypes, indicating a negative correlation between immune infiltration and survival prognosis in gliomas. IDH mutations had a negative correlation with glioma immunity. Immunity-high had higher tumor stemness and epithelial-mesenchymal transition scores and included more high-grade tumors than immunity-low, suggesting that elevated immunity is associated with tumor progression in gliomas. Immunity-high had higher tumor mutation burden and more frequent somatic copy number alterations, suggesting a positive association between tumor immunity and genomic instability in gliomas.

Conclusions

The identification of immune-specific glioma subtypes has potential clinical implications for the immunotherapy of gliomas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-020-02030-w.

Immunological classification of renal cell carcinoma patients based on phenotypic analysis of immune check-point molecules

OBJECTIVES

To clarify comprehensive immunological signature patterns of tumour tissue-infiltrating lymphocytes in patients with renal cell carcinoma and show its clinical significance.

MATERIALS AND METHODS

We investigated the surface marker expressions of tumour tissue-infiltrating lymphocytes quantitatively and classified them based on their functional populations. We extracted 109 sets of tumour tissue-infiltrating lymphocytes from 80 patients who underwent surgical resection of renal cell carcinoma, of which 44 tumour tissue-infiltrating lymphocytes were multiply extracted from 15 patients. Each tumour tissue-infiltrating lymphocyte was characterised on the basis of functional T-cell populations using ten surface marker expressions measured by flow cytometry.

RESULTS

All sets of the tumour tissue-infiltrating lymphocytes were classified into three groups, which correlated significantly with Fuhrman grade (OR 0.253, 95% CI 0.094-0.678, P = 0.006). Importantly, both overall metastasis-free survival (HR 0.449, 95% CI 0.243-0.832, P = 0.011) and recurrence-free survival (HR 0.475, 95% CI 0.238-0.948, P = 0.035) of the patients with the higher marker expressions were significantly inferior to those of the patients with the lower marker expressions by multivariate analysis. Six specific genes for this classification identified by microarray analysis verified our results using the TCGA KIRC data set. In addition, we discovered the presence of intra-tumoural diversity in the classification of 3 (20%) of the 15 patients.

CONCLUSIONS

This study showed that the presence of classable diversity in the immunological signature of tumour tissue-infiltrating lymphocytes correlated with prognosis and tumour aggressiveness that was observed even within individual tumours in some patients with renal cell carcinoma.