Regulatory T-cells activated in metastatic draining lymph nodes possibly suppress cancer immunity in cancer tissues of head and neck squamous cell cancer.

Regulatory T cells (Tregs) play an important role in creating an immunosuppressive microenvironment in cancer tissues. However, the mechanisms by which Tregs are activated and suppress cancer immunity remain unclear. To elucidate these mechanisms, we performed a T cell receptor (TCR) repertoire analysis of Tregs and conventional T cells in peripheral blood, draining lymph nodes (DLNs), and cancer tissues of patients with head and neck squamous cell cancer (HNSCC). We found that the TCR repertoire was skewed in cancer tissue and metastatic DLNs (M-DLNs) compared with non-metastatic DLNs, and TCR repertoire similarities in Tregs and CD8+ T cells between M-DLNs and cancer tissue were high compared with those at other sites. These results suggest that Tregs and CD8+ T cells are activated in M-DLNs and cancer tissues by cancer antigens, such as neoantigens, and shared antigens and Tregs suppress CD8+ T cell function in a cancer antigen-specific manner in M-DLNs and cancer tissue. Moreover, M-DLNs might be a source of Tregs and CD8+ T cells recruited into the cancer tissue. Therefore, targeting Tregs in M-DLNs in an antigen-specific manner is expected to be a novel immunotherapeutic strategy for HNSCCs.

Endobronchial spread of adenocarcinoma is a distinct pattern of invasion and associated with inferior clinical outcomes in lung adenocarcinoma.

AIM: The spread of lung adenocarcinoma cells into the bronchi and bronchioles is not well documented. We termed this histological finding "endobronchial spreading of adenocarcinoma" (EBSA) and investigated its prevalence and clinical significance. METHODS AND RESULTS: We reviewed 320 resected specimens from patients diagnosed with invasive adenocarcinoma, and EBSA was observed in 144 patients (45%). EBSA was significantly associated with advanced pathological stage, higher histological grade, larger tumour invasion, lymphovascular infiltration, and spread through air spaces. Patients with EBSA had significantly shorter relapse-free survival (RFS) and cancer-specific survival (CSS) in univariate analysis (P < 0.001). In a subgroup analysis of patient with small-sized (invasion size ≤30 mm) adenocarcinoma in the localized stage, EBSA was an independent inferior prognostic indicator in multivariate analysis. In a subgroup analysis of patients with small-sized Grade 1 nonmucinous adenocarcinoma (n = 61), EBSA was observed in 11 patients, and the presence of EBSA was associated with significantly shorter RFS and CSS (P = 0.026 and P = 0.001, respectively). CONCLUSION: Our results demonstrated that EBSA is a significant risk factor for disease recurrence and cancer-related deaths. EBSA can be regarded as a distinctive pattern of invasion and its recognition can be beneficial in the diagnosis of lung adenocarcinoma.

PTEN loss in intraductal carcinoma of the prostate has low incidence in Japanese patients.

Clinical and genomic features of prostate cancer (PCa) vary considerably between Asian and Western populations. PTEN loss is the most frequent abnormality in intraductal carcinoma of the prostate (IDC-P) in Western populations. However, its prevalence and significance in Asian populations have not yet been well studied. In the present study, we evaluated PTEN expression in IDC-P in a Japanese population and its association with ERG expression. This study included 45 and 59 patients with PCa with and without IDC-P, respectively, who underwent radical prostatectomy. PTEN loss was observed in 10 patients with PCa with IDC-P (22%) and nine patients with PCa without IDC-P (17%). ERG expression was relatively frequent in patients with PCa with PTEN loss, although a significant difference was not observed. The co-occurrence of PTEN loss and ERG expression was observed in four patients with PCa with IDC-P and one without IDC-P. PTEN loss and ERG expression did not affect progression-free survival, regardless of the presence of IDC-P. The frequency of PTEN loss in IDC-P is lower in Asian patients than in Western patients. Our results indicate that mechanisms underlying IDC-P in Asian populations are different from those of Western populations.

Immune Status of Cervical Lymph Nodes in Head and Neck Cancer-A Surgical Oncology Perspective.

Neck dissection for cervical lymph node metastasis is an established procedure for head and neck cancer (HNC). However, with the advent of immunotherapy, head and neck surgical oncologists need to rethink removing all lymph nodes, including those with immune function. We investigated the anti-cancer immune response of the cervical lymph nodes in four patients with human papillomavirus type 16 (HPV16)-positive head and neck squamous cell carcinoma. Using lymphocytes extracted from local, metastatic, and non-metastatic lymph nodes and peripheral blood from these patients, we performed an intracellular flow cytometric cytokine assay using anti-IFNγ and anti-TNF-α monoclonal antibodies to detect HPV16 E6- and E7-specific T cells. HPV status and p16 immunostaining were determined by in situ detection using the HPV RNAscope method and immunohistochemistry. In one case, E6-specific and E7-specific CD8+ T cells were detected in proximal metastatic nodes and distal non-metastatic nodes. This finding suggests that non-metastatic nodes should be preserved for their immune function during neck dissection and that the immune function of non-metastatic lymph nodes is important when administering immunotherapy. In this context, head and neck surgical oncologists treating HNC should consider the place of immunotherapy and neck dissection in the treatment of HNC.

Diagnostic approach for classic Hodgkin lymphoma in small samples with an emphasis on PD-L1 expression and EBV harboring in tumor cells: a brief review from morphology to biology.

Classic Hodgkin lymphoma (CHL) was first described in 1832 by Thomas Hodgkin, and is characterized by a small number of Hodgkin and Reed-Sternberg cells in a rich inflammatory background. However, even in this modern era, due to the histological and biological overlap with CHL and other B-cell malignancies, including mediastinal grey zone lymphoma and other lymphomas accompanied by "Hodgkinoid cells", their discrimination is challenging and sometimes impossible. The complexity and ambiguity of the boundaries of CHL and its related diseases make the definition of CHL unresolved. Our group has studied the significance of PD-L1 expression and infection of Epstein-Barr virus (EBV) in the diagnosis of CHL, emphasizing their pathological role, clinical significance, and high reproducibility even in daily clinical practice. In this review, we summarize the diagnostic strategy of CHL and its histological lookalikes based on neoplastic PD-L1 expression and infection of EBV, and attempt a reappraisal of the definition of CHL.

Diagnostic Utility of STAT6 and pSTAT6 Immunohistochemistry for Distinguishing Classic Hodgkin Lymphoma and Peripheral T-Cell Lymphoma With Hodgkin and Reed-Sternberg-like Cells.

Peripheral T-cell lymphomas (PTCLs), particularly nodal lymphomas of T-follicular helper cell origin, may include Hodgkin/Reed-Sternberg (HRS)-like cells in their microenvironment. These HRS-like cells are morphologically indistinguishable from HRS cells of classic Hodgkin lymphoma (CHL). Therefore, PTCLs with HRS-like cells pose a differential diagnosis vis-à-vis CHL. A previous study reported that, in contrast to HRS cells, programmed death-ligand 1 (PD-L1) expression is rare in HRS-like cells of PTCLs and suggested that PD-L1 immunohistochemistry is useful to differentiate HRS cells and HRS-like cells. In this study, we analyzed 21 patients with PTCL with HRS-like cells and 34 patients with CHL and assessed the diagnostic utility of STAT6, pSTAT6, and pSTAT3 immunohistochemistry in distinguishing HRS cells from HRS-like cells. In addition, we also performed PD-L1 immunohistochemistry to reconfirm its utility in distinguishing the 2 diseases. Compared with HRS cells in CHLs, HRS-like cells in PTCLs showed significantly less positivity for STAT6 (9.6% vs. 70%, P <0.001), pSTAT6 (9.6% vs. 70%, P <0.001), and PD-L1 (9.6% vs. 85%, P <0.001). Thus, we reconfirmed the diagnostic utility of PD-L1 immunohistochemistry in distinguishing CHLs from PTCLs with HRS-like cells. In contrast, both HRS-like and HRS cells were highly associated with pSTAT3 expression, with no significant difference in positive cell frequency (86% vs. 91%, P =0.66). On the basis of these findings, we conclude that, in addition to PD-L1, STAT6 and pSTAT6 immunohistochemistry are helpful diagnostic tools to distinguish CHLs from PTCLs with HRS-like cells.

The Immunology of DLBCL.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy and is the most common type of malignant lymphoid neoplasm. While some DLBCLs exhibit strong cell-autonomous survival and proliferation activity, others depend on interactions with non-malignant cells for their survival and proliferation. Recent next-generation sequencing studies have linked these interactions with the molecular classification of DLBCL. For example, germinal center B-cell-like DLBCL tends to show strong associations with follicular T cells and epigenetic regulation of immune recognition molecules, whereas activated B-cell-like DLBCL shows frequent genetic aberrations affecting the class I major histocompatibility complex. Single-cell technologies have also provided detailed information about cell-cell interactions and the cell composition of the microenvironment of DLBCL. Aging-related immunological deterioration, i.e., immunosenescence, also plays an important role in DLBCL pathogenesis, especially in Epstein-Barr virus-positive DLBCL. Moreover, DLBCL in "immune-privileged sites"-where multiple immune-modulating mechanisms exist-shows unique biological features, including frequent down-regulation of immune recognition molecules and an immune-tolerogenic tumor microenvironment. These advances in understanding the immunology of DLBCL may contribute to the development of novel therapies targeting immune systems.

Establishment of Mucoepidermoid Carcinoma Cell Lines from Surgical and Recurrence Biopsy Specimens.

Patients with advanced/recurrent mucoepidermoid carcinoma (MEC) have a poor prognosis. This study aimed to establish and characterize human mucoepidermoid carcinoma cell lines from the initial surgical specimen and biopsy specimen upon recurrence from the same patient to provide a resource for MEC research. MEC specimens from the initial surgical procedure and biopsy upon recurrence were used to establish cell lines. The established cell lines were cytogenetically characterized using multi-color fluorescence in situ hybridization and detection, and the sequence of the CRTC1-MAML2 chimeric gene was determined. Furthermore, the susceptibility of head and neck mucoepidermoid carcinoma to standard treatment drugs such as cisplatin, 5-fluorouracil, and cetuximab was investigated. We successfully established unique MEC cell lines, AMU-MEC1, from an initial surgical specimen and AMU-MEC1-R1 and AMU-MEC1-R2 from the recurrent biopsy specimen in the same patient. These cell lines exhibited epithelial morphology and developed in vitro-like cobblestones. They shared eight chromosomal abnormalities, including der(19)ins(19;11)(p13;?), which resulted in a chimeric CRTC1-MAML2 gene, indicating the same origin of the cell lines. The susceptibility of all cell lines to cisplatin and 5-fluorouracil was low. Interestingly, EGFR dependency for cell growth decreased in AMU-MEC-R1 and AMU-MEC-R2 but was retained in AMU-MEC1. These cytogenetic and biochemical findings suggest that the established cell lines can be used to investigate the disease progression mechanisms and develop novel therapeutics for MEC.

Trametinib improves Treg selectivity of anti-CCR4 antibody by regulating CCR4 expression in CTLs in oral squamous cell carcinoma.

Regulatory T-cells (Tregs) play a major role in suppressing anti-tumor immune responses. Mogamulizumab, an anti-CC chemokine receptor type 4 (CCR4) monoclonal antibody, depletes effector Tregs (eTregs). However, the clinical efficacy of mogamulizumab was limited in phase Ia/Ib studies for solid tumors (NCT01929486); the finding suggests that mogamulizumab may also deplete beneficial CCR4+CD8+ T-cells in patients. Therefore, we focused on CTLs and aimed to identify a way to protect CCR4+ CTLs. Here, we evaluated the association of CCR4 expression in cytotoxic T-lymphocytes (CTLs) with antigen and cytokine stimulations and kinase inhibition using cytomegalovirus antigen instead of tumor antigen. CCR4 expression in CTLs was induced by antigen stimulation (mean 3.14-29.0%), enhanced by transforming growth factor-ß1 (TGF-ß1) (mean 29.0-51.2%), and downregulated by trametinib with (mean 51.2-11.4%) or without TGF-ß1 treatment (mean 29.0-6.98%). Phosphorylation of ERK in CD8+ T-cells was suppressed by trametinib. Regarding the effect on immunological function of CTL, trametinib reduced cytokine production but not affected cytotoxicity. Importantly, trametinib alleviated CTL reduction by anti-CCR4 antibody without affecting eTreg depletion because CCR4 expression in eTregs was not downregulated. In conclusion, combination therapy with trametinib may improve the clinical efficacy of mogamulizumab.

Pathological and Molecular Features of Nodal Peripheral T-Cell Lymphomas.

Peripheral T-cell lymphomas (PTCLs) are uncommon neoplasms derived from mature T cells or NK cells. PTCLs comprise numerous disease entities, with over 30 distinct entities listed in the latest WHO classification. They predominantly affect adults and elderly people and usually exhibit an aggressive clinical course with poor prognosis. According to their presentation, PTCLs can be divided into nodal, extranodal or cutaneous, and leukemic types. The most frequent primary sites of PTCLs are lymph nodes, with over half of cases showing nodal presentation. Nodal PTCLs include ALK-positive and ALK-negative anaplastic large cell lymphoma; nodal T-cell lymphoma with T follicular helper cell origin; and PTCL, not otherwise specified. Adult T-cell leukemia/lymphoma also frequently affects lymph nodes. Recent pathological and molecular findings in nodal PTCLs have profoundly advanced the identification of tumor signatures and the refinement of the classification. Therefore, the therapies and pathological diagnosis of nodal PTCLs are continually evolving. This paper aims to provide a summary and update of the pathological and molecular features of nodal PTCLs, which will be helpful for diagnostic practice.

Hodgkin Lymphoma: Biology and Differential Diagnostic Problem.

Hodgkin lymphomas (HLs) are lymphoid neoplasms that are morphologically defined as being composed of dysplastic cells, namely, Hodgkin and Reed-Sternberg cells, in a reactive inflammatory background. The biological nature of HLs has long been unclear; however, our understanding of HL-related genetics and tumor microenvironment interactions is rapidly expanding. For example, cell surface overexpression of programmed cell death 1 ligand 1 (CD274/PD-L1) is now considered a defining feature of an HL subset, and targeting such immune checkpoint molecules is a promising therapeutic option. Still, HLs comprise multiple disease subtypes, and some HL features may overlap with its morphological mimics, posing challenging diagnostic and therapeutic problems. In this review, we summarize the recent advances in understanding the biology of HLs, and discuss approaches to differentiating HL and its mimics.

An Update on the Pathology and Molecular Features of Hodgkin Lymphoma.

Hodgkin lymphomas (HLs) are lymphoid neoplasms derived from B cells and consist histologically of large neoplastic cells known as Hodgkin and Reed-Sternberg cells and abundant reactive bystander cells. HLs include two main types, classic HL (CHL) and nodular lymphocyte predominant HL (NLPHL). Recent molecular analyses have revealed that an immune evasion mechanism, particularly the PD-1/PD-L1 pathway, plays a key role in the development of CHL. Other highlighted key pathways in CHL are NF-κB and JAK/STAT. These advances have dramatically changed the treatment for CHL, particularly relapsed/refractory CHL. For example, PD-1 inhibitors are now widely used in relapsed/refractory CHL. Compared with CHL, NLPHL is more characterized by preserved B cell features. Overlapping morphological and molecular features between NLPHL and T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) have been reported, and biological continuity between these two entities has been highlighted. Some THRLBCLs are considered to represent progression from NLPHLs. With considerable new understanding becoming available from molecular studies in HLs, therapies and classification of HLs are continually evolving. This paper offers a summary of and update on the pathological and molecular features of HLs for a better understanding of the diseases.

Cytokeratin 5/6 expression in pT1 bladder cancer predicts intravesical recurrence in patients treated with bacillus Calmette-Guérin instillation.

Bacillus Calmette-Guérin (BCG) instillation is the gold standard for the treatment of patients with pT1 bladder cancer but causes severe adverse effects. Few predictive factors have been established for intravesical recurrence and/or stage progression in bladder cancer. We analysed 138 patients who underwent transurethral resection of bladder tumour and were pathologically confirmed to have stage pT1 bladder cancer. Of these, 72 patients (52.2%) received intravesical BCG instillation, 12 patients (8.7%) demonstrated stage progression, and five patients (3.6%) died of the disease. The number of patients who received BCG instillation was more in the group with multifocal tumours than that in the group with unifocal tumours (p=0.0034). Among 53 patients (38.4%) who demonstrated cytokeratin 5/6 (CK5/6) expression, 15 patients (28.3%) showed CK5/6 expression in more than 10% of tumour cells and 38 patients (71.7%) showed CK5/6 expression in 1-10% of tumour cells. CK5/6 expression was observed in both invasive and non-invasive components in 15 patients (28.3%), only in invasive components in 30 patients (56.6%), and only in non-invasive components in eight patients (15.1%). Furthermore, CK5/6 expression was observed in tumour cells only in front of the invasive component and stroma in 24 patients. The proportion of CK5/6-expressing tumour cells in the invasive component was significantly higher than that in the non-invasive component (p<0.001). The follow-up period for patients who received BCG tended to be shorter than that in the non-BCG patients. The CK5/6-positive group displayed significantly shorter recurrence-free survival (RFS) than the CK5/6-negative group (p=0.0412). Importantly, CK5/6 expression was a significant predictive factor of inferior RFS in the BCG instillation group (p=0.0197). In contrast, CK5/6 expression was not significantly associated with RFS in the non-BCG instillation group (p=0.841). Thus, CK5/6 expression can be a predictive marker for RFS in patients with pT1 bladder cancer and can provide critical information for patient care.

In Situ PD-L1 Expression in Oral Squamous Cell Carcinoma Is Induced by Heterogeneous Mechanisms among Patients.

The expression of programmed death ligand-1 (PD-L1) is controlled by complex mechanisms. The elucidation of the molecular mechanisms of PD-L1 expression is important for the exploration of new insights into PD-1 blockade therapy. Detailed mechanisms of the in situ expression of PD-L1 in tissues of oral squamous cell carcinomas (OSCCs) have not yet been clarified. We examined the mechanisms of PD-L1 expression focusing on the phosphorylation of downstream molecules of epidermal growth factor (EGF) and interferon gamma (IFN-γ) signaling in vitro and in vivo by immunoblotting and multi-fluorescence immunohistochemistry (MF-IHC), respectively. The in vitro experiments demonstrated that PD-L1 expression in OSCC cell lines is upregulated by EGF via the EGF receptor (EGFR)/PI3K/AKT pathway, the EGFR/STAT1 pathway, and the EGFR/MEK/ERK pathway, and by IFN-γ via the JAK2/STAT1 pathway. MF-IHC demonstrated that STAT1 and EGFR phosphorylation was frequently shown in PD-L1-positive cases and STAT1 phosphorylation was correlated with lymphocyte infiltration and EGFR phosphorylation. Moreover, the phosphorylation pattern of the related molecules in PD-L1-positive cells differed among the cases investigated. These findings indicate that PD-L1 expression mechanisms differ depending on the tissue environment and suggest that the examination of the tissue environment and molecular alterations of cancer cells affecting PD-L1 expression make it necessary for each patient to choose the appropriate combination drugs for PD-1 blockade cancer treatment.

PD-L1-expressing extranodal diffuse large B-cell lymphoma, NOS with and without PD-L1 3'-UTR structural variations.

Immune evasion mediated by PD-L1 plays an important role in the development of B-cell malignancies. However, PD-L1 expression is infrequently observed in tumor cells of extranodal diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS). Other than copy number alterations, PD-L1 is aberrantly upregulated by structural variations in the 3'-UTR of PD-L1. We report four cases with PD-L1 expression on tumor cells, including two with structural variations in the 3'-UTR of PD-L1 and two without. Our report demonstrates the presence of a small number of "immune evasion-type" extranodal DLBCL, NOS cases.

TGFB1 mRNA expression is associated with poor prognosis and specific features of inflammation in ccRCC.

To determine whether TGFB1 affects the immune microenvironment of ccRCC, we investigated the association between TGFB1 expression and clinicopathological features. Tissue microarray was generated from 158 total or partial nephrectomy samples and 12 tumor-adjacent normal kidney tissue. TGFB1 expression was assessed by RNA in situ hybridization and quantified using ImageJ software. TGFB1 was significantly upregulated in ccRCC tissue than in normal kidney tissues (P = 1.03 × 10-9). Tumors with a high WHO/ISUP grade had higher TGFB1 expression levels (P = 7.05 × 10-3). Of 139 patients with localized ccRCC and whose follow-up data were available, those in the TGFB1-high group displayed significantly shorter relapse-free survival than those in the TGFB1-low group (P = 0.0251). TGFB1 expression was significantly upregulated in patients who developed distant metastasis after surgery (n = 12) than in patients without metastasis (n = 127; P = 0.00167). TGFB1 expression positively correlated with the number of PD-L1-positive cells in the tumor stroma (P = 0.0206, ρ = 0.163). Furthermore, TGFB1 expression was associated with the formation of tertiary lymphoid structures. TGF-ß1 is a prognostic indicator of worse outcome for ccRCC and might be a therapeutic target in advanced ccRCC. Our data provide new insights into the association between tumor biology and tumor microenvironment in ccRCC.

Lymphocyte-depleted classic Hodgkin lymphoma with primary extranodal disease: Two cases that highlight the combination of immunodeficiency and immune escape in the pathogenesis.

Neoplastic programmed cell death ligand 1 (PD-L1) expression, activated by PD-L1 gene alterations, is strongly associated with classic Hodgkin lymphoma (CHL). This association enabled a diagnostic consensus for lymphocyte-depleted CHL (LD-CHL), a previously enigmatic disease. We describe two patients with LD-CHL and primary extranodal disease. One patient was a 92-year-old female (Case #1) with a large mass that involved the uterus combined with swollen lymph nodes in the pelvic cavity. The second patient was a 76-year-old female (Case #2) with human T-cell leukemia virus type 1 (HTLV-1) who initially exhibited massive bone marrow involvement without peripheral lymphadenopathies. Biopsies of these tumors from the cervix uteri and bone marrow, respectively, revealed lesions rich in Hodgkin and Reed-Sternberg (H-RS) cells and diminished populations of other cell populations. Immunohistochemistry demonstrated that these H-RS cells expressed CD30, BOB1, and fascin, but not CD15, CD20, PAX5, or OCT2. They also expressed PD-L1, which led to our preferred diagnosis of LD-CHL in both patients. Epstein-Barr virus was associated with LD-CHL in Case #1, but not in Case #2. Both patients were deemed too frail for treatment. They died of disease at 1 (Case #1) and 15 months (Case #2) after the diagnosis. These findings highlight the abnormal biological behavior of this immune-escape-related lymphoid neoplasm in patients with immunodeficiency due to immune senescence and HTLV1 infection.

Diagnostic utility of programmed cell death ligand 1 (clone SP142) immunohistochemistry for malignant lymphoma and lymphoproliferative disorders: A brief review.

The programmed cell death 1 (PD1)/PD1 ligand (PD-L1) axis plays an important role in tumor cell escape from immune control and has been most extensively investigated for therapeutic purposes. However, PD-L1 immunohistochemistry is still not used widely for diagnosis. We review the diagnostic utility of PD-L1 (by clone SP142) immunohistochemistry in large-cell lymphomas, mainly consisting of classic Hodgkin lymphoma (CHL) and diffuse large B-cell lymphoma (DLBCL). Neoplastic PD-L1 (nPD-L1) expression on Hodgkin and Reed-Sternberg cells is well-established among prototypic CHL. Of note, EBV+ CHL often poses a challenge for differential diagnosis from peripheral T-cell lymphoma with EBV+ non-malignant large B-cells; their distinction is based on the lack of PD-L1 expression on large B-cells in the latter. The nPD-L1 expression further provides a good diagnostic consensus for CHL with primary extranodal disease conceivably characterized by a combined pathogenesis of immune escape of tumor cells and immunodeficiency. Compared with CHL, the nPD-L1 expression rate is much lower in DLBCL, highlighting some specific subgroups of intravascular large B-cell lymphoma, primary mediastinal large B-cell lymphoma, and EBV+ DLBCL. They consist of nPD-L1-positive and -negative subgroups, but their clinicopathological significance remains to be elucidated. Microenvironmental PD-L1 positivity on immune cells may be associated with a favorable prognosis in extranodal DLBCL. PD-L1 (by SP142) immunohistochemistry has helped us to understand the immune biology of lymphoid neoplasms possibly related by immune escape and/or immunodeficiency. However, knowledge of these issues remains limited and should be clarified for diagnostic consensus in the future.

Clinicopathologic Analysis of Primary Adrenal Diffuse Large B-Cell Lymphoma: A Reappraisal of 23 Japanese Patients Based on EBV Association and PD-L1 Expression in Tumor Cells.

Primary adrenal diffuse large B-cell lymphoma (PA-DLBCL) is rare. We investigate 23 Japanese patients with PA-DLBCL to understand the clinicopathologic features and biological behavior of this disease. The 17 males and 6 females had a median age of 74 years (range: 40 to 86 y). Tumor cells harbored Epstein-Barr virus-encoded small RNA (EBER) in 9 (39%) samples, including samples from the 2 patients with methotrexate-associated B-cell lymphoproliferative disorder. Programmed cell death ligand 1 (PD-L1) expression was detected in tumor cells of 6 (26%) samples, including 1 EBER+ and 5 EBER- samples. Four (17%) patients exhibited an intravascular proliferating pattern, and all 4 patient samples showed positive staining for PD-L1 in tumor cells. Among those patients, 3 showed intravascular proliferating pattern accompanied by a diffuse extravascular proliferation of tumor cells, and 1 patient was diagnosed with intravascular large B-cell lymphoma. We divided the 23 patients into 3 groups: EBER+ (n=9, 39%), EBER-PD-L1+ (n=5, 22%), and EBER-PD-L1- (n=9, 39%). A comparison of the outcomes among the 3 groups showed significant differences in overall survival (P=0.034). The EBER+ group had the worst prognosis, and the EBER-PD-L1- group had the best prognosis. We also compared the outcomes among the 3 groups that received rituximab-containing chemotherapies. Both the overall survival and progression-free survival were significantly different among these groups (P<0.001 and P=0.002, respectively). In conclusion, we evaluated 3 types of PA-DLBCL and found that each had unique clinical, pathologic, and prognostic features. Our results suggested that immune senescence, iatrogenic immunodeficiency, and immune evasion contribute to the development of PA-DLBCL.

Improving function of cytotoxic T-lymphocytes by transforming growth factor-ß inhibitor in oral squamous cell carcinoma.

Immunotherapy with immune-checkpoint therapy has recently been used to treat oral squamous cell carcinomas (OSCCs). However, improvements in current immunotherapy are expected because response rates are limited. Transforming growth factor-ß (TGF-ß) creates an immunosuppressive tumor microenvironment (TME) by inducing the production of regulatory T-cells (Tregs) and cancer-associated fibroblasts and inhibiting the function of cytotoxic T-lymphocytes (CTLs) and natural killer cells. TGF-ß may be an important target in the development of novel cancer immunotherapies. In this study, we investigated the suppressive effect of TGF-ß on CTL function in vitro using OSCC cell lines and their specific CTLs. Moreover, TGFB1 mRNA expression and T-cell infiltration in 25 OSCC tissues were examined by in situ hybridization and multifluorescence immunohistochemistry. We found that TGF-ß suppressed the function of antigen-specific CTLs in the priming and effector phases in vitro. Additionally, TGF-ß inhibitor effectively restored the CTL function, and TGFB1 mRNA was primarily expressed in the tumor invasive front. Interestingly, we found a significant negative correlation between TGFB1 mRNA expression and the CD8+ T-cell/Treg ratio and between TGFB1 mRNA expression and the Ki-67 expression in CD8+ T-cells, indicating that TGF-ß also suppressed the function of CTLs in situ. Our findings suggest that the regulation of TGF-ß function restores the immunosuppressive TME to active status and is important for developing new immunotherapeutic strategies, such as a combination of immune-checkpoint inhibitors and TGF-ß inhibitors, for OSCCs.