The Expression of Three Negative Co-Stimulatory B7 Family Molecules in Small Cell Lung Cancer and Their Effect on Prognosis

Plasma cell signatures predict prognosis and treatment efficacy for lung adenocarcinoma

PURPOSE

This study aims to identify key genes regulating tumor infiltrating plasma cells (PC) and provide new insights for innovative immunotherapy.

METHODS

Key genes related to PC were identified using machine learning in lung adenocarcinoma (LUAD) patients. A prognostic model called PC scores was developed using TCGA data and validated with GEO cohorts. We assessed the molecular background, immune features, and drug sensitivity of the high PC scores group. Real-time PCR was utilized to assess the expression of hub genes in both localized LUAD patients and LUAD cell lines.

RESULTS

We constructed PC scores based on seventeen PC-related hub genes (ELOVL6, MFI2, FURIN, DOK1, ERO1LB, CLEC7A, ZNF431, KIAA1324, NUCB2, TXNDC11, ICAM3, CR2, CLIC6, CARNS1, P2RY13, KLF15, and SLC24A4). Higher age, TNM stage, and PC scores independently predicted shorter overall survival. The AUC value of PC scores for one year, three years, and five years of overall survival were 0.713, 0.716, and 0.690, separately. The nomogram model that integrated age, stage, and PC scores showed significantly higher predictive value than stage alone (P < 0.01). High PC scores group exhibited an immune suppressing microenvironment with lower B, CD8 + T, CD4 + T, and dendritic cell infiltration. Docetaxel, gefitinib, and erlotinib had lower IC50 in high PC groups (P < 0.001). After validation through the local cohort and in vitro experiments, we ultimately confirmed three key potential targets: MFI2, KLF15, and CLEC7A.

CONCLUSION

We proposed a prediction mode which can effectively identify high-risk LUAD patients and found three novel genes closely correlated with PC tumor infiltration.

New Emerging Targets in Cancer Immunotherapy: The Role of B7-H3

Immune checkpoints (ICs) are molecules implicated in the fine-tuning of immune response via co-inhibitory or co-stimulatory signals, and serve to secure minimized host damage. Targeting ICs with various therapeutic modalities, including checkpoint inhibitors/monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and CAR-T cells has produced remarkable results, especially in immunogenic tumors, setting a paradigm shift in cancer therapeutics through the incorporation of these IC-targeted treatments. However, the large proportion of subjects who experience primary or secondary resistance to available IC-targeted options necessitates further advancements that render immunotherapy beneficial for a larger patient pool with longer duration of response. B7-H3 (B7 Homolog 3 Protein, CD276) is a member of the B7 family of IC proteins that exerts pleiotropic immunomodulatory effects both in physiologic and pathologic contexts. Mounting evidence has demonstrated an aberrant expression of B7-H3 in various solid malignancies, including tumors less sensitive to current immunotherapeutic options, and has associated its expression with advanced disease, worse patient survival and impaired response to IC-based regimens. Anti-B7-H3 agents, including novel mAbs, bispecific antibodies, ADCs, CAR-T cells, and radioimmunotherapy agents, have exhibited encouraging antitumor activity in preclinical models and have recently entered clinical testing for several cancer types. In the present review, we concisely present the functional implications of B7-H3 and discuss the latest evidence regarding its prognostic significance and therapeutic potential in solid malignancies, with emphasis on anti-B7-H3 modalities that are currently evaluated in clinical trial settings. Better understanding of B7-H3 intricate interactions in the tumor microenvironment will expand the oncological utility of anti-B7-H3 agents and further shape their role in cancer therapeutics.

B7-H3/CD276 and small-cell lung cancer: What's new?

Immunotherapy revolutionized the treatment landscape of several cancers, including small-cell lung cancer (SCLC), with a huge number of practice-changing trials, and becoming a new frontier for their management. The addition of an anti-PD-L1, atezolizumab or durvalumab, to platinum/etoposide regimen became the standard of care for first-line therapy of extensive-stage (ES)-SCLC with the 12 months median survival exceeded for the first time. Nevertheless, most patients show primary or acquired resistance to anti-PD-L1 therefore new promising therapeutic immune-targets are under clinical investigation in several solid tumors. Among these, B7-H3, also known as CD276, is a member of the B7 family overexpressed in tumor tissues, including SCLC, while showing limited expression in normal tissues becoming an attractive and promising target for cancer immunotherapy. B7-H3 plays a dual role in the immune system during the T-cell activation, acting as a T-cell costimulatory/coinhibitory immunoregulatory protein, and promoting pro-tumorigenic functions such as tumor migration, invasion, metastases, resistance, and metabolism. Immunohistochemistry, flow cytometry, and immunofluorescence were the most used methods to assess B7-H3 expression levels and validate a possible relationship between B7-H3 staining patterns and clinicopathological features in lung cancer patients. To date, there are no clinically available therapeutics/drugs targeting B7-H3 in any solid tumors. The most promising preliminary clinical results have been reported by DS7300a and HS-20093, both are antibody-drug conjugates, that are under investigation in ongoing trials for the treatment of pretreated SCLC. This review will provide an overview of B7-H3 and corresponding inhibitors and the clinical development in the management of SCLC.

Targeting DNA methylation and B7-H3 in RB1-deficient and neuroendocrine prostate cancer

Aberrant DNA methylation has been implicated as a key driver of prostate cancer lineage plasticity and histologic transformation to neuroendocrine prostate cancer (NEPC). DNA methyltransferases (DNMTs) are highly expressed, and global DNA methylation is dysregulated in NEPC. We identified that deletion of DNMT genes decreases expression of neuroendocrine lineage markers and substantially reduced NEPC tumor development and metastasis in vivo. Decitabine, a pan-DNMT inhibitor, attenuated tumor growth in NEPC patient-derived xenograft models, as well as retinoblastoma gene (RB1)-deficient castration-resistant prostate adenocarcinoma (CRPC) models compared with RB1-proficient CRPC. We further found that DNMT inhibition increased expression of B7 homolog 3 (B7-H3), an emerging druggable target, via demethylation of B7-H3. We tested DS-7300a (i-DXd), an antibody-drug conjugate targeting B7-H3, alone and in combination with decitabine in models of advanced prostate cancer. There was potent single-agent antitumor activity of DS-7300a in both CRPC and NEPC bearing high expression of B7-H3. In B7-H3-low models, combination therapy of decitabine plus DS-7300a resulted in enhanced response. DNMT inhibition may therefore be a promising therapeutic target for NEPC and RB1-deficient CRPC and may sensitize B7-H3-low prostate cancer to DS-7300a through increasing target expression. NEPC and RB1-deficient CRPC represent prostate cancer subgroups with poor prognosis, and the development of biomarker-driven therapeutic strategies for these populations may ultimately help improve patient outcomes.

An immune checkpoint-based signature predicts prognosis and chemotherapy response for patients with small cell lung cancer

BACKGROUND

Therapeutic options for small cell lung cancer (SCLC), a particularly lethal malignancy, remain limited. Members of the B7-CD28 family are compelling targets for immune checkpoint blockade strategies, which involve activating, inhibiting, and fine-tuning the T cell immune response. However, their clinical features and significance have not been explored comprehensively.

METHOD

We enrolled 228 patients with an initial diagnosis of SCLC, including 77 cases from Cbioportal and a validation cohort of 151 cases with qPCR data. Kaplan-Meier analysis and LASSO Cox model were used to identify a signature based on the B7-CD28 family, which was applied for accurate prediction of chemotherapy benefit and prognosis for SCLC patients. In addition, we applied bioinformatics analysis to explore potential signature-related molecular mechanisms and the immune landscape.

RESULTS

The mutation profiles of healthy tissues and SCLC tissues were distinct. A signature consisting of seven genes (CD86, ICOSLG, CD276, CD28, CTLA-4, PDCD1, and TMIGD2) was identified and applied to group patients based on risk level (high-risk and low-risk), producing two groups for which survival outcomes differed significantly (HR = 3.81, 95% CI: 2.16-6.74, P < 0.001). The immune checkpoint-based signature accurately predicted patient outcomes for the selected training and validation sets. Notably, low-risk patients were more likely to benefit from chemotherapy and showed greater immune activation. Additionally, time-dependent ROC curves and C-index analysis confirmed that the immune checkpoint-based signature has excellent predictive power for prognosis and chemotherapy benefit compared to clinically recognized parameters. Finally, multivariate analysis confirmed the identified signature as an independent risk factor for prognosis and chemotherapeutic response.

CONCLUSION

We systematically obtained a comprehensive molecular profile for B7-CD28 family members in SCLC patients, from which we produced a reliable and robust prognostic immune checkpoint-based signature with the potential to improve prognostic stratification and therapy strategies for SCLC patients.

Immune checkpoint of B7-H3 in cancer: from immunology to clinical immunotherapy

Immunotherapy for cancer is a rapidly developing treatment that modifies the immune system and enhances the antitumor immune response. B7-H3 (CD276), a member of the B7 family that plays an immunoregulatory role in the T cell response, has been highlighted as a novel potential target for cancer immunotherapy. B7-H3 has been shown to play an inhibitory role in T cell activation and proliferation, participate in tumor immune evasion and influence both the immune response and tumor behavior through different signaling pathways. B7-H3 expression has been found to be aberrantly upregulated in many different cancer types, and an association between B7-H3 expression and poor prognosis has been established. Immunotherapy targeting B7-H3 through different approaches has been developing rapidly, and many ongoing clinical trials are exploring the safety and efficacy profiles of these therapies in cancer. In this review, we summarize the emerging research on the function and underlying pathways of B7-H3, the expression and roles of B7-H3 in different cancer types, and the advances in B7-H3-targeted therapy. Considering different tumor microenvironment characteristics and results from preclinical models to clinical practice, the research indicates that B7-H3 is a promising target for future immunotherapy, which might eventually contribute to an improvement in cancer immunotherapy that will benefit patients.

Clinical significance and correlation of PD-L1, B7-H3, B7-H4, and TILs in pancreatic cancer

BACKGROUND

B7 molecules play significant roles in regulating tumor immunity, but their expression patterns and immuno-biological correlations in pancreatic cancer (PaCa) have not been fully discussed.

METHODS

RNA-sequencing data of B7 molecules of PaCa samples in the Cancer Genome Atlas (TCGA) dataset was downloaded from the UCSC Xena to assess the expression, correlation, and mutation of the B7 family in PaCa. Next, two PaCa tissue microarrays (TMAs, Cat. HPanA150CS02 and HPanA120Su02) were obtained from Outdo BioTech (Shanghai, China). To detect the expression levels of PD-L1, B7-H3 and B7-H4, immunohistochemistry (IHC) staining was performed on these TMAs.

RESULTS

Most B7 molecules, including B7-1, B7-2, PD-L1, B7-DC, B7-H2, and B7-H5 exhibited similar expression patterns, but B7-H3, B7-H4, B7-H6, and B7-H7 showed outlier expression patterns compared with other B7 molecules. Besides, B7 molecules were genetically stable and exhibited low alteration frequency. IHC staining indicated PD-L1, B7-H3, and B7-H4 were up-regulated in PaCa tissues and showed uncorrelated expression patterns. Furthermore, high expression of PD-L1 and B7-H3 indicated poor-differentiated grades in PaCa. PD-L1 was positively, but B7-H4 was negatively correlated with CD8+ TILs infiltration in PaCa. Moreover, combined PD-L1 and B7-H4 expression was a novel subtyping strategy in PaCa, namely patients with both high PD-L1 and B7-H4 expression exhibited decreased CD8+ TILs infiltration in tumor tissues.

CONCLUSION

Overall, we systemically analyzed the expression patterns of B7 molecules and proposed a novel subtyping strategy in PaCa. Patients with both high PD-L1 and B7-H4 expression exhibited the immuno-cold phenotype, which may be not suitable for immunotherapy.

Genetic Alteration and Their Significance on Clinical Events in Small Cell Lung Cancer

Introduction

Small cell lung cancer (SCLC), an aggressive subtype of lung cancer characterized by the development of neuroendocrine tumors, is prone to distant metastasis, resistant to platinum-based drugs and has a poor prognosis. The development of next-generation sequencing technology (NGS) has led to the identification of many genetic alterations in SCLC. Few druggable targeted molecules can be used in clinical practice. Currently, NGS is widely employed in routine clinical practice of non-small cell lung cancer to assist in therapeutic options and prognosis evaluation. This study aims to investigate genes involved in small cell lung cancer (SCLC), their occurrence and their significance in clinical events.

Methods

Tumor tissue specimens from 18 Chinese SCLC patients were collected through a 520 cancer‐related genes panel for next-generation sequencing. First, the association between sequence results and clinical outcomes was examined. Subsequently, data on clinical pathology and sequencing results were analyzed.

Results

The Kaplan–Meier curve displayed a significant reduction in PFS for SCLC patients with LRP1B or MAP3K13 mutations. Overall survival (OS) of SCLC patients with MSH6 mutation was significantly higher than those with SPEN mutation.

Conclusion

Next-generation sequencing demonstrates that the genetic landscape of SCLC. Mutation status of LRP1B, MAP3K13, MSH6 and SPEN has prognostic significance, which might be potential therapeutic targets. We found possible genes and related signaling pathways that affect metastasis. These results can improve our understanding of the mutation characteristics of SCLC and identify potential biomarkers to guide targeted therapies.

Co-deficiency of B7-H3 and B7-H4 identifies high CD8 + T cell infiltration and better prognosis in pancreatic cancer

Background

Immunotherapy is a novel hotspot for the treatment of pancreatic adenocarcinoma (PAAD). However, potential biomarkers which could identify the inflamed tumor microenvironment (TME) are urgently required.

Methods

In the present study, we measured the levels of B7-H3, B7-H4, and major tumor-infiltrating immune cells (TIICs) using bioinformatics analyses and immunohistochemistry (IHC) staining on PAAD samples represented in the tissue microarray (TMA) format. Statistical analysis and figures exhibition were performed using R 4.1.0, SPSS 26.0, and GraphPad Prism 6.0.

Results

B7-H3 and B7-H4 were up-regulated in PAAD compared with para-tumor tissues, and their expression exhibited no tight correlation in PAAD tissues. B7-H3 and B7-H4 were lowly expressed in well-differentiated PAAD tissues and correlated with poorly differentiated grades. Besides, single B7-H3 or B7-H4 expression exhibited limited prognostic value, but co-deficiency of B7-H3 and B7-H4 predicted a better prognosis in PAAD. Moreover, co-deficiency of B7-H3 and B7-H4 indicated immuno-hot tumors with high CD8 + T cell infiltration.

Conclusions

Overall, combined B7-H3 and B7-H4 expression is a promising stratification strategy to assess prognosis and immunogenicity in PAAD, which could be used as a novel classifier in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09294-w.