The tissue distribution and significance of B7-H4 in laryngeal carcinoma

Programmed death-ligand 1 and tumor-infiltrating lymphocytes (TILs) - low TIL density may predict poorer long-term prognosis in T1 laryngeal cancer

We evaluated the prognostic role of programmed death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in T1 glottic laryngeal squamous cell carcinoma (LSCC). T1 glottic LSCC patients (n = 174) treated at five Finnish university hospitals between 2003 and 2013 were included. Tissue microarray (TMA) blocks were used for PD-L1 immunohistochemistry. TILs were scored from intratumoral and stromal regions in whole tissue sections. Of 174 patients, 92 (53%) had negative, 66 (38%) intermediate, and 16 (9%) high PD-L1 levels. Of 80 patients whose TILs were analyzed, 50 (63%) had low and 30 (38%) high stromal TIL density. Patients with a local recurrence or a new primary tumor of the larynx had lower TIL density than had other patients (p = 0.047). High PD-L1 expression with low stromal TIL density was associated with inferior 5-year disease-specific survival (85% vs. 100%, p = 0.02). In conclusion, in patients treated for T1 glottic LSCC, low stromal TIL density was associated with local recurrences and new primary tumors of the larynx. High PD-L1 expression with low stromal TIL density may be associated with worse survival in T1 glottic LSCC.

The prognostic impact of B7-H3 and B7-H4 in head and neck squamous cell carcinoma

PURPOSE

Immune checkpoint inhibition is a therapeutic option in many cancer entities. In head and neck squamous cell carcinoma (HNSCC) targeting of the PD-1/PD-L1 (B7-H1) axis is approved in recurrent/metastatic disease and is being explored in the curative setting. Here, we evaluated two related members of the B7 family, B7-H3 & B7-H4, for their prognostic impact under standard treatment.

METHODS

A tissue microarray (TMA) of a single center HNSCC cohort was stained for B7-H3 and B7-H4. Staining intensity and the number of tumor cells stained were assessed, and the expression was scored according to an established algorithm. Staining scores were correlated with clinicopathological parameters and associated with patient survival. mRNA levels of both proteins were associated with patient outcome using the TCGA dataset.

RESULTS

mRNA levels of B7-H3 and B7-H4 were not significantly associated with patient survival. TMA analysis revealed interpretable protein staining in 408 samples. Strong staining was the most frequent category for B7-H3 and no staining for B7-H4. In patients with p16-negative oropharyngeal SCC (OPSCC) and in a pooled cohort consisting of p16-negative OPSCC, laryngeal, hypopharyngeal and oral cavity SCC, strong B7-H3 expression was associated with better overall survival. For the latter cohort, this was in part due to reduced lymph node involvement. B7-H3 expression in p16-positive OPSCC and B7-H4 expression were not associated with outcome.

CONCLUSION

Despite a possible role in tumor immune escape, B7-H3 was associated with favorable prognosis in HPV-negative HNSCC in our cohort. The underlying mechanisms and a potential impact for B7-H3 targeting remain to be elucidated.

Association of immune response with overall and disease-free survival in laryngeal squamous cell carcinomas

OBJECTIVES

This study aimed to examine the relationship between checkpoint receptors (PD-1, PD-L1, PD-L2, CTLA-4) and lymphoid infiltration level (TILs) with prognostic features of patients with laryngeal squamous cell carcinoma (LSCC).

METHODS

A retrospective study was designed at a tertiary referential university hospital between April 2008 and December 2020. The surgical specimen of the patients who met the eligibility criteria were re-examined histopathological, sociodemographic, clinical, pathological, and follow-up findings of patients were determined. The impact of PD-1, PD-L1, PD-L2, CTLA4, and TILs levels for the presence of cancer recurrence, disease-specific mortality, overall survival (OS), disease-free survival (DFS) was investigated.

RESULTS

Forty-five patients with LSCC were included in the study. The mean follow-up period was 48.3 ± 14.3 months (min: 36, max 84). TILs scores were detected significantly lower in patients with distant metastasis and recurrence (p = 0.046 and 0.010). Also, only TILs was a significant risk factor for recurrence and survival among the PD-1, PD-L1, PD-L2, CTLA-4, and TILs (HR = 0.217 CI: 0.070-0.679, p = 0.009 and HR = 0.566, CI: 0,321-980, p = 0.048). Similarly, for the TILs score: > 1 was significant for DFS. (Long-Rank = 0.009). The examined markers and TILs scores were not a significant predictive factor for OS.

CONCLUSION

An increase in TILs density in LSCCs is associated with a better prognosis. However, PD-1, PD-L1, PD-L2, CTLA-4 could not be associated with prognosis. Controlled studies combined with immunotherapy treatment results are needed to reveal their role as a marker and prognostic factor of the anti-tumor immune response.

B7-H4 expression is upregulated by PKCδ activation and contributes to PKCδ-induced cell motility in colorectal cancer

Introduction

B7-H4 is overexpressed in colorectal cancer (CRC) and plays an important role in tumor growth and immunosuppression. However, the exact mechanism that regulates B7-H4 expression remains largely unknown. Here, we investigated whether protein kinase C δ (PKCδ) regulates the expression of B7-H4 in CRC.

Methods

By using immunohistochemical (IHC) and immunofluorescence (IF) staining, we analyzed the expression of B7-H4 and phospho-PKCδ (p-PKCδ) in 225 colorectal tumor samples and determined the clinical significance of the expression patterns. In vitro experiments were performed with the CRC cell lines HCT116 and SW620 to detect the effect of PKCδ activation on B7-H4 expression, and xenograft-bearing mice were treated with rottlerin to monitor the expression of B7-H4 and tumor metastasis.

Results

The B7-H4 expression level was significantly correlated with the p-PKCδ level (r = 0.378, P < 0.001) in tumor tissues. Coexpression of p-PKCδ and B7-H4 was significantly associated with moderate/poor differentiation (P = 0.024), lymph node metastasis (P = 0.001) and advanced Dukes’ stage (P = 0.002). Western blot analysis showed that Phorbol-12-Myristate-13-Acetate (TPA) increased B7-H4 expression in a concentration-dependent manner and that rottlerin abrogated the TPA-induced increase in B7-H4 expression. The protein levels of B7-H4 and p-STAT3 were significantly reduced by a PKCδ-specific siRNA. Moreover, the STAT3 inhibitor cryptotanshinone significantly decreased the B7-H4 protein level in CRC cells. Knockdown of B7-H4 or PKCδ suppressed cell migration and motility. Rottlerin also inhibited B7-H4 expression and tumor metastasis in vivo.

Conclusion

The B7-H4 expression level is significantly correlated with the p-PKCδ level and tumor metastasis in CRC samples. B7-H4 expression is upregulated by STAT3 activation via PKCδ and plays roles in PKCδ-induced cancer cell motility and metastasis, suggesting that the PKCδ/STAT3/B7-H4 axis may be a potential therapeutic target for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02567-1.

Non-cytomembrane PD-L1: An atypical target for cancer

Programmed death ligand 1 (PD-L1) has conventionally been considered as a type I transmembrane protein that can interact with its receptor, programmed cell death 1 (PD-1), thus inducing T cell deactivation and immune escape. However, targeting the PD-1/PD-L1 axis has achieved adequate clinical responses in very few specific malignancies. Recent studies have explored the extracellularly and subcellularly located PD-L1, namely, nuclear PD-L1 (nPD-L1), cytoplasmic PD-L1 (cPD-L1), soluble PD-L1 (sPD-L1), and extracellular vesicle PD-L1 (EV PD-L1), which might shed light on the resistance to anti-PD1/PDL1 therapy. In this review, we summarize the four atypical localizations of PD-L1 with a focus on their novel functions, such as gene transcription regulation, therapeutic efficacy prediction, and resistance to various cancer therapies. Additionally, we highlight that non-cytomembrane PD-L1s are of significant cancer diagnostic value and are promising therapeutic targets to treat cancer.

IL-17 Affects the Progression, Metastasis, and Recurrence of Laryngeal Cancer via the Inhibition of Apoptosis through Activation of the PI3K/AKT/FAS/FASL Pathways

Background

Cytokines play important roles in the development and prognosis of laryngeal cancer (LC). Interleukin-17 (IL-17) from a distinct subset of CD4+ T cells may significantly induce cancer-elicited inflammation to prevent tumor immune surveillance.

Methods

The expression levels of IL-17 were examined among 60 patients with LC. Immunofluorescence colocalization experiments were performed to verify the localization of IL-17 and FAS/FASL in Hep-2 and Tu212 cells. The role of IL-17 was determined using siRNA techniques in the LC cell line.

Results

In the LC patients, cytokines were dysregulated in LC tissues compared with normal tissues. It was found that IL-17 was overexpressed in a cohort of 60 LC tumors paired with nontumor tissues. Moreover, high IL-17 expression was significantly associated with the advanced T category, the late clinical stage, differentiation, lymph node metastasis, and recurrence. In addition, the time course expression of FAS and FASL was observed after stimulation and treatment with the IL-17 stimulator. Finally, in vitro experiments demonstrated that IL-17 functioned as an oncogene by inhibiting the apoptosis of LC cells via the PI3K/AKT/FAS/FASL pathways.

Conclusions

In summary, these findings demonstrated for the first time the role of IL-17 as a tumor promoter and a prometastatic factor in LC and indicated that IL-17 may have an oncogenic role and serve as a potential prognostic biomarker and therapeutic target in LC.

Prognostic role of programmed death ligand 1 (PD-L1) and the immune microenvironment in laryngeal carcinoma

OBJECTIVES

The immune system is crucial in the evolution of head and neck cancer. Programmed cell death ligand 1 (PD-L1) seems to rely on close relations between neoplastic cells and immune cells in the tumor microenvironment. The main aim of this study was to apply univariate/multivariate analysis to investigate the prognostic significance of PD-L1, tumor-infiltrating lymphocytes (TILs), and tertiary lymphoid structures (TLS) in laryngeal carcinoma (LSCC).

MATERIALS AND METHODS

PD-L1 (in terms of combined positive score [CPS]), TILs and TLS were assessed at pathology on 70 consecutive samples of LSCC.

RESULTS

A CPS ≥ 1 coincided with a lower recurrence rate (RR) (p = 0.007) and longer disease-free survival (DFS) than a CPS < 1 (p = 0.0027). Cases with higher TIL counts showed a lower RR (p = 0.036) and longer DFS than those with lower TIL counts (p = 0.0062). Cases revealing TLS had a lower RR (p = 0.004) and longer DFS (p = 0.0034) than those with no TLS. On multivariate analysis, the presence of TLS retained its positive prognostic value (p = 0.024), while CPS remained significant as regards disease recurrence (p = 0.050).

CONCLUSIONS

PD-L1 seems to be an indirect marker of effective anti-tumor response in LSCC, possibly being expressed as a result of a greater immune pressure on cancer cells. The presence of TLS emerged as a positive prognostic factor. Further prospective studies are needed to characterize the role of PD-L1 as a marker of anti-tumor immune response and prognostic factor in LSCC, also with regard to the effectiveness of immunotherapeutic protocols.

The B7-H4 gene induces immune escape partly via upregulating the PD-1/Stat3 pathway in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is associated with high mortality rates worldwide. The costimulatory molecule, B7-H4, a member of the B7 family, plays an important role in immune regulation, mainly by inhibiting the proliferation of T cells to achieve a negative regulatory T cell immune response. The mechanism of action of B7-H4 in non-small cell lung cancer is unknown at present. Tumor tissues from 71 patients subjected to radical pneumonectomy were examined, along with NSCLC cells and BALB/c mice. Among the 71 NSCLC cases, overall and recurrence-free survival rates were significantly lower in those displaying high B7-H4 expression. Mechanistic analyses showed that B7-H4 promoted the growth and metastasis of non-small cell lung cancer tumor tissues in mice through effects on CD8⁺ T cell apoptosis. Data from western blot experiments further suggested that B7-H4 induced CD8⁺ T cell death, both in vitro and in vivo, and affecting the PD-1/Stat3 pathway and promoting immune escape of tumor cells. Our collective findings support the potential utility of B7-H4 gene expression as a marker of NSCLC prognosis and provide a novel strategy for targeted therapy.

Laryngeal Tumor Microenvironment

Tumor microenvironment has been extensively studied in various forms of cancer, like head and neck squamous cell carcinoma. Progress in the field revealed the prognostic significance of the various components of the tumor's ecosystem and led to changes in treatment strategies, like including immunotherapy as an important tool. In this chapter, the microenvironment of tumors with a special interest in laryngeal cancer will be described. The issues assessed include innate immune response factors, like neutrophils, neutrophil extracellular traps (NET), platelets, macrophages M1 or M2, dendritic cells, natural killer cells, as well as adaptive immunity aspects, like cytotoxic, exhausted and regulatory T cells, and immune checkpoints (PD-1/PD-L1, CTLA4). Also, stroma-associated factors, like fibroblasts, fibrosis, extracellular matrix, vessels and perineural invasion, hypoxia and cancer metabolism aspects, as well as the pre-metastatic niche, exosomes and cGAS-STING, are reviewed.

B7-H4, a promising target for immunotherapy

The coinhibitory molecule B7-H4, an important member of the B7 family, is abnormally expressed in tumors, inflammation and autoimmune diseases. B7-H4 negatively regulates T cell immune response and promotes immune escape by inhibiting the proliferation, cytokine secretion, and cell cycle of T cells. Moreover, B7-H4 plays an extremely important role in tumorigenesis and tumor development including cell proliferation, invasion, metastasis, anti-apoptosis, etc. In addition, B7-H4 has the other biological functions, such as protection against type 1 diabetes (T1D) and islet cell transplantation. Therefore, B7-H4 has been identified as a novel marker or a therapeutic target for the treatment of tumors, inflammation, autoimmune diseases, and organ transplantation. Here, we summarized the expression profiles, physiological and pathological functions, and regulatory mechanisms of B7-H4, the signaling pathways involved, as well as B7-H4-based immunotherapy.