Residual tumor micro-foci and overwhelming regulatory T lymphocyte infiltration are the causes of bladder cancer recurrence

Regulatory T Cells but Not Tumour-Infiltrating Lymphocytes Correlate with Tumour Invasion Depth in Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common skin malignancy worldwide. Current evidence suggests tumour-infiltrating lymphocytes (TILs) may influence the clinical outcomes of patients with BCC. The present study aimed to profile the infiltrative characteristics of stromal TILs and regulatory T cells (Treg cells) in the tumour centre (TC), tumour periphery (TP), and normal adjacent tissue (NAT) of BCC. A total of 111 samples from 43 cutaneous BCC cases were examined for TIL (CD3+) and Treg cell (FOXP3+/CD3+) expression using immunohistochemical techniques. The correlations of Treg cells with TILs, invasion depth, and tumour morphological risk were analysed. We identified a high mean proportion of Treg cells within the tumour (TC = 46.9%, TP = 56.1%, NAT = 51.8%) despite a relatively low median of TILs (TC = 12.7%, TP = 10.3%, NAT = 3.6%), supporting the classification of BCC as a cold tumour. A significant positive correlation was observed between the proportion of Treg cells and sTILs (ρ = 0.325, p < 0.001), suggesting a predominant role of TILs in the infiltration of Treg cells. An inverse correlation discovered between Treg cells and tumour invasion depth (r = −0.36, p = 0.017) might indicate Treg cells’ anti-tumour capacity in BCC.

Modified immunoscore improves the prediction of progression-free survival in patients with non-muscle-invasive bladder cancer: A digital pathology study

Tumour-infiltrating lymphocytes (TIL), known to be of prognostic value in various solid tumours, have been in the focus of research in the last years. TIL are often quantified via IMMUNOSCORE ® (IS), a scoring system based on TIL cell densities. Recent studies were able to replicate these findings for muscle-invasive bladder cancer (MIBC), however data regarding non-muscle-invasive bladder cancer (NMIBC) are scarce. This study aimed to evaluate the value of a modified Immunoscore (mIS) as a predictive marker for NMIBC prognosis using tissue-micro-arrays (TMAs). We analysed two TMAs containing 316 samples from 158 patients with NMIBC, stained for CD3, CD8, CD45RO and FOXP3. Stained TIL were captured by digital pathology, cumulated, averaged, and reported as density (stained cells per mm²). The mIS was then constructed based on density of all four immune-cell types. Clinical, pathological and follow-up data were collected retrospectively. Univariable and multivariable cox regression analysis was performed to assess the potential value of mIS as a predictor for progression free survival (PFS) and recurrence-free-survival (RFS). Patients within "European Organisation for Research and Treatment of Cancer" (EORTC) risk groups were further substratified in high mIS and low mIS subgroups. Finally log-rank test was used to compare the different survival curves. The median age in our cohort was 68 years (Interquartile Range (IQR): 60 - 76), and 117 (74%) patients were male. A total of 26 patients (16.5%) were classified as EORTC low risk, 45 (28.5%) as intermediate risk and 87 (55.1%) as high risk. Patients in the EORTC high risk group with low mIS showed a shorter PFS in comparison to high mIS (HR 2.9, CI 0.79 - 11.0, p=0.082). In contrast, no predictive potential regarding PFS was observed in intermediate or low risk groups. Furthermore, mIS was not able to predict RFS in any EORTC risk group. mIS could be utilized to predict prognosis more accurately in high-risk patients with NMIBC by identifying those with higher or lower risk of progression. Therefore, mIS could be used to allocate these highrisk patients to more streamlined follow-up or more aggressive treatment strategies.

BCG invokes superior STING-mediated innate immune response over radiotherapy in a carcinogen murine model of urothelial cancer

Radiation and bacillus Calmette-Guérin (BCG) instillations are used clinically for treatment of urothelial carcinoma, but the precise mechanisms by which they activate an immune response remain elusive. The role of the cGAS-STING pathway has been implicated in both BCG and radiation-induced immune response; however, comparison of STING pathway molecules and the immune landscape following treatment in urothelial carcinoma has not been performed. We therefore comprehensively analyzed the local immune response in the bladder tumor microenvironment following radiotherapy and BCG instillations in a well-established spontaneous murine model of urothelial carcinoma to provide insight into activation of STING-mediated immune response. Mice were exposed to the oral carcinogen, BBN, for 12 weeks prior to treatment with a single 15 Gy dose of radiation or three intravesical instillations of BCG (1 × 108  CFU). At sacrifice, tumors were staged by a urologic pathologist and effects of therapy on the immune microenvironment were measured using the NanoString Myeloid Innate Immunity Panel and immunohistochemistry. Clinical relevance was established by measuring immune biomarker expression of cGAS and STING on a human tissue microarray consisting of BCG-treated non-muscle-invasive urothelial carcinomas. BCG instillations in the murine model elevated STING and downstream STING-induced interferon and pro-inflammatory molecules, intratumoral M1 macrophage and T-cell accumulation, and complete tumor eradication. In contrast, radiotherapy caused no changes in STING pathway or innate immune gene expression; rather, it induced M2 macrophage accumulation and elevated FoxP3 expression characteristic of immunosuppression. In human non-muscle-invasive bladder cancer, STING protein expression was elevated at baseline in patients who responded to BCG therapy and increased further after BCG therapy. Overall, these results show that STING pathway activation plays a key role in effective BCG-induced immune response and strongly indicate that the effects of BCG on the bladder cancer immune microenvironment are more beneficial than those induced by radiation. © 2021 The Pathological Society of Great Britain and Ireland.

Evaluation of lymphocyte-specific programmed cell death protein 1 receptor expression and cytokines in blood and urine in canine urothelial carcinoma patients

Urothelial carcinoma (UC) is the most common urinary tumour in dogs. Despite a range of treatment options, prognosis remains poor in dogs. In people, breakthroughs with checkpoint inhibitors have established new standards of care for muscle-invasive bladder cancer patients and elevated levels of programmed cell death protein 1 (PD-1) suggest immune checkpoint blockade may be a novel target for therapy. The goal of this study was to determine if canine UC patients express elevated levels of lymphocyte-specific PD-1 and/or urinary cytokine biomarkers compared to healthy dogs. Paired blood and urine were evaluated in 10 canine UC patients, five cystitis patients and 10 control dogs for lymphocyte-specific PD-1 expression via flow cytometry and relative cytokine expression. In UC patients, PD-1 expression was significantly elevated on CD8⁺ lymphocytes in urine samples. UC patients had a higher CD4:CD8 ratio in their urine compared to healthy dogs, however, there was no significant variation in the CD8:Treg ratio between any group. Cystitis patients had significantly elevated levels of CD4⁺ T cells, CD8⁺ T cells and Tregs in their blood samples compared to UC patients and healthy dogs. Cytokine analysis demonstrated significant elevations in urinary cytokines (granulocyte-macrophage colony-stimulating factor, interferon-gamma [IFN-γ], interleukin (IL)-2, IL-6 IL-7, IL-8 and IL-15, IP-10, KC-like, IL-18, monocyte chemoattractant protein-1 and tumour necrosis factor-alpha). Several of these cytokines have been previously correlated with both lymphocyte-specific PD-1 expression (IFN-γ, IL-2, IL-7 and IL-15) in muscle-invasive urothelial carcinoma in humans. Our results provide evidence of urinary lymphocyte PD-1 expression and future studies could elucidate whether veterinary UC patients will respond favourably to anti-PD-1 immune checkpoint inhibitor therapy.

Prognostic significance of CD4-positive regulatory T cells in tumor draining lymph nodes from patients with bladder cancer

Introduction and methods

To clarify the role of CD4⁺ regulatory T cells in bladder cancer, we investigated the frequency of these cells in tumor draining lymph nodes of 50 patients with bladder cancer who underwent radical cystectomy using flow cytometry method. We also assessed their association with prognosis and survival.

Results

On average, 30.13 ± 2.17% of lymphocytes in draining lymph nodes from patients with bladder cancer were positive for both CD4 and FOXP3 molecules. Analyses also showed that 9.92 ± 0.8% of CD4⁺ lymphocytes had a regulatory phenotype (CD4⁺CD25⁺FOXP3⁺CD127^low/neg). The frequency of total CD4⁺FOXP3⁺ lymphocytes as well as regulatory T cells was significantly greater in patients with at least one tumor-involved lymph node compared to those with tumor-free nodes (P = 0.026 and P = 0.036, respectively). Mean FOXP3 expression in CD4⁺ lymphocytes was greater in patients with stage IV compared with those in stage III (P = 0.046). No other significant associations were found between the frequency of regulatory T cells and other clinicopathological characteristics or patient survival.

Conclusions

The increased frequency of regulatory T cells in patients with involved lymph nodes suggests that these cells may negatively regulate antitumor immune responses in draining lymph nodes. Our findings may have implications for immunotherapy-based treatments for bladder cancer.

Mitotic activity index and CD25+ lymphocytes predict risk of stage progression in non-muscle invasive bladder cancer

In urothelial cell type non-muscle invasive urinary bladder carcinoma, TNM stage and WHO grade are widely used to classify patients into low and high‑risk groups for prognostic and therapeutic decision-making. However, stage and grade reproducibility and prediction accuracy are wanting. This may lead to suboptimal treatment. We evaluated whether proliferation features, nuclear area of the epithelial cancer cells and the composition of stromal and tumor infiltrating lymphocytes have independent prognostic value. In 183 primary non-muscle invasive bladder cancer patients with long follow-up (median for stage progression cohort: 119 months, range 5-173; median for tumor recurrence cohort: 82, range 3-165) proliferation features Ki67, PPH3 and Mitotic Activity Index (MAI), Mean Nuclear Area (MNA), lymphocyte subsets (CD8+, CD4+, CD25+) and plasma cells (CD138+) were assessed on consecutive sections. Post-resection instillation treatments (none, mitomycin, BCG) were strictly standardized during the intake period. Risk of recurrence was associated with expression of Ki67 (≤ 39 vs. > 39) and Multifocality (p = 0.01). Patients with low Ki67 had a higher recurrence rate than those with high Ki67. Lymphocyte composition did not predict recurrence. Stage progression was strongly associated with high values for MAI (>15) and CD25+ (>0.2%). In a multivariate analysis the combination of MAI and CD25+ was the single most prognostic feature (p<0.001). Validation of these results in additional, independent studies is warranted.

The Tumor Microenvironment of Bladder Cancer

Bladder cancer has been well known as immunotherapy-responsive disease as intravesical therapy with BCG has been the standard of care for non-muscle invasive disease for several decades. In addition, immune checkpoint inhibitors have dramatically changed the treatment of metastatic bladder cancer. However, only a small fraction of patients with bladder cancer can benefit from these therapies. As immunotherapies act on the tumor microenvironment, understanding it is essential to expand the efficacy of modern treatments. The bladder cancer microenvironment consists of various components including tumor cells, immune cells, and other stromal cells, affecting each other via immune checkpoint molecules, cytokines, and chemokines. The development of an antitumor immune response depends on tumor antigen recognition by antigen presenting cells and priming and recruitment of effector T cells. Accumulated evidence shows that these processes are impacted by multiple types of immune cells in the tumor microenvironment including regulatory T cells, tumor-associated macrophages, and myeloid derived suppressor cells. In addition, recent advances in genomic profiling have shed light on the relationship between molecular subtypes and the tumor microenvironment. Finally, emerging evidence has shown that multiple factors can impact the tumor microenvironment in bladder cancer, including tumor-oncogenic signaling, patient genetics, and the commensal microbiome.

The multifaceted immune regulation of bladder cancer

Bladder cancer is an important public health concern owing to its prevalence, high recurrence risk and treatment failures. Maintaining the equilibrium between prompt and effective immunity and an excessive and protracted immune response is critical for successful immune defence. This delicate balance is ensured by intrinsic or extrinsic immunoregulatory mechanisms. Intrinsic control of immune cell activation is mediated by stimulatory and inhibitory receptors expressed on the effector cell itself, whereas extrinsic control is mediated via other immune cells by cell-cell contact and/or secretion of inhibitory factors. Tumours can exacerbate these immunosuppressive pathways, fostering a tolerant microenvironment. These mechanisms have previously been poorly described in urothelial carcinoma, but a growing body of evidence highlights the key role of immune regulation in bladder cancer. This process includes immune checkpoints (mostly programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1)), as well as regulatory T cells, myeloid-derived suppressor cells, tumour-associated macrophages and type 2 innate and adaptive lymphocytes. For each component, quantitative and qualitative alterations, clinical relevance and potential targeting strategies are currently being explored. An improved understanding of immune regulation pathways in bladder cancer development, recurrence and progression will help in the design of novel diagnostic and prognostic tools as well as treatments.

Accurate Quantification of Residual Cancer Cells in Pelvic Washing Reveals Association with Cancer Recurrence Following Robot-Assisted Radical Cystectomy

PURPOSE

Bladder cancer recurrence following cystectomy remains a significant cause of bladder cancer specific mortality. Residual cancer cells contribute to cancer recurrence due to tumor spillage or undetectable preexisting micrometastatic tumor clones. We detected and quantified residual cancer cells in pelvic washing using ultradeep targeted sequencing. We compared the levels of residual cancer cells with clinical variables and cancer recurrence.

MATERIALS AND METHODS

The primary tumor specimen was available in 17 patients who underwent robot-assisted radical cystectomy. All tumors had negative surgical margins. Pelvic washes and blood were collected intraoperatively before and after robot-assisted radical cystectomy, after pelvic lymph node dissection and in the suction fluid collected during the procedure. Two-step sequencing, including whole exome sequencing followed by ultradeep targeted sequencing (× greater than 50,000), was done to quantify residual cancer cells in each sample. Eight patients were excluded from study due to sample quality issues. The final analysis cohort comprised 9 patients. The residual cancer cell level was quantified for each sample as the relative cancer cell fraction and compared between time points. The peak relative cancer cell fraction of each patient was correlated with clinical and pathological variables.

RESULTS

Residual cancer cells were detected in approximately half of the pelvic washing specimens during or after but not before robot-assisted radical cystectomy. Higher residual cancer cell levels were associated with aggressive variant histology and cancer recurrence. Verifying the feasibility of using residual cancer cells as a novel biomarker for recurrence requires larger cohorts.

CONCLUSIONS

Detection of residual cancer cells in intraoperative peritoneal washes of patients with bladder cancer who undergo radical cystectomy may represent a robust biomarker of tumor aggressiveness and metastatic potential.

Expression of miR-490-5p, miR-148a-3p and miR-608 in bladder cancer and their effects on the biological characteristics of bladder cancer cells

Changes in the expression of miR-490-5p, miR-148a-3p and miR-608 in bladder cancer tissues were studied. A total of 30 patients with bladder cancer who had surgical resection in the Hunan Provincial People's Hospital (Changsha, China) from April 2015 to August 2016 were selected. RT-qPCR was used to detect the expression levels of miR-490-5p, miR-148a-3p and miR-608. The expression vectors of miR-490-5p, miR-148a-3p and miR-608 were respectively transfected and divided into three groups: blank cell group, gene transfection group (groups A-C) and negative transfection group (NC group). CCK8 was used to detect cell proliferation and flow cytometry was used to detect the condition of apoptosis of each group, and the Transwell chamber was used to detect the invasion ability of the cells. After the transfection, the expression level of miR-490-5p in group A was significantly higher than that in the NC and blank groups, and the expression level of miR-148a-3p in group B was significantly higher than that in the NC and blank groups. The expression level of miR-608 in group C was significantly higher than that in the NC and blank groups (P<0.001). The survival rates of the cells in groups A-C were significantly lower than those in the NC and blank groups at 48 and 72 h (P<0.001). After the transfection, the number of invasive cells and the apoptosis rates in groups A-C were significantly higher than those in the NC and blank groups (P<0.05). miR-490-5p, miR-148a-3p and miR-608 promoted proliferation of bladder cancer T24 cells and inhibited apoptosis of the cells and showed potential to become a new target for the future treatment of bladder cancer.

White matter microstructure alterations correlate with terminally differentiated CD8+ effector T cell depletion in the peripheral blood in mania: Combined DTI and immunological investigation in the different phases of bipolar disorder

BACKGROUND

White matter (WM) microstructural abnormalities and, independently, signs of immunological activation were consistently demonstrated in bipolar disorder (BD). However, the relationship between WM and immunological alterations as well as their occurrence in the various phases of BD remain unclear.

METHOD

In 60 type I BD patients - 20 in manic, 20 in depressive, 20 in euthymic phases - and 20 controls we investigated: (i) diffusion tensor imaging (DTI)-derived fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD) using a tract-based spatial statistics (TBSS) approach; (ii) circulating T cell subpopulations frequencies, as well as plasma levels of different cytokines; (iii) potential relationships between WM and immunological data.

RESULTS

We found: (i) a significant widespread combined FA-RD alteration mainly in mania, with involvement of the body of corpus callosum (BCC) and superior corona radiata (SCR); (ii) significant increase in CD4+ T cells as well as significant decrease in CD8+ T cells and their subpopulations effector memory (CD8+ CD28-CD45RA-), terminal effector memory (CD8+ CD28-CD45RA+) and CD8+ IFNγ+ in mania; (iii) a significant relationship between WM and immunological alterations in the whole cohort, and a significant correlation of FA-RD abnormalities in the BCC and SCR with reduced frequencies of CD8+ terminal effector memory and CD8+ IFNγ+ T cells in mania only.

CONCLUSIONS

Our data show a combined occurrence of WM and immunological alterations in mania. WM abnormalities highly correlated with reduction in circulating CD8+ T cell subpopulations that are terminally differentiated effector cells prone to tissue migration, suggesting that these T cells could play a role in WM alteration in BD.

Prediction of intravesical recurrence of non-muscle-invasive bladder cancer by evaluation of intratumoral Foxp3+ T cells in the primary transurethral resection of bladder tumor specimens

Patients with a history of non-muscle-invasive bladder cancer sometimes have recurrence of tumors after transurethral resection of bladder tumor treatment. To find factors related to the recurrence of non-muscle-invasive bladder cancer, we examined tissue specimens taken at transurethral resection of bladder tumor as an initial treatment. We revealed the association between prognosis of non-muscle-invasive bladder cancer and infiltration of Foxp3⁺ T cells that suppress anti-tumor immunity in 115 primary non-muscle-invasive bladder cancer patients retrospectively identified and followed for at least 3 months after primary transurethral resection. In immunohistological staining, we counted the number of cells positive for CD3 and positive for CD3 and Foxp3 together and calculated the percentage of Foxp3⁺ T cells among the CD3⁺ T cells. The recurrence-free survival rate was calculated by the Kaplan-Meier method, and a Cox regression analysis of recurrence factors was performed. The median (interquartile range) percentage of Foxp3⁺ T cells in all cases was 17.1% (11.9, 11.4–23.3%). Compared by risk stratification, it was 11.4% (10.4, 7.8–18.2%) in the low-risk group (n = 32), 16.8% (12.6, 11.6–24.2%) in the intermediate-risk group (n = 45), and 22.0% (9.7, 16.4–26.1%) in the high-risk group (n = 38). The Kaplan-Meier survival analysis indicated that the Foxp3⁺ T cell high group (≥ 17.1%) had a worse RFS rate than did the low group (< 17.1%) (P = 0.006). In multivariate analysis, the percentage of Foxp3⁺ T cells was an independent risk factor for intravesical recurrence (hazard ratio 2.25). Thus, peritumoral Foxp3⁺ T cell infiltration was correlated to risk stratification and recurrence-free survival. Therefore, the percentage of Foxp3⁺ T cells in tumor specimens may predict a risk for intravesical recurrence.

Tumor-infiltrating immune cell subpopulations influence the oncologic outcome after intravesical Bacillus Calmette-Guérin therapy in bladder cancer

Although Bacillus Calmette-Guérin (BCG) is the most successful immunotherapy for high-risk non-muscle-invasive bladder cancer, approximately 30% of patients are unresponsive to treatment. New biomarkers are important to identify patients who will benefit most from BCG during a worldwide BCG shortage. Local immune cell subsets were measured on formalin-fixed, paraffin-embedded tissue sections of bladder cancer by immunohistochemistry, using monoclonal antibodies to tumor-associated macrophages (TAMs; CD68, CD163), B-lymphocytes (CD20) and T-lymphocyte subsets (CD3, CD4, CD8, GATA3, T-bet, FOXP3 and CD25). Cell densities in the lamina propria without invasion, at the invasive front if present, in the papillary tumor stroma, and in the neoplastic urothelium were calculated. Twenty-nine (72.5%) of 40 patients were classified as BCG responders after a mean follow-up of 35.3 months. A statistically significant association was observed for BCG failure with low density of CD4+ and GATA3+ T-cells, and increased expression of FOXP3+ and CD25+ regulatory T-cells (Tregs) as well as CD68+ and CD163+ TAMs. Survival analysis demonstrated prolonged recurrence-free survival (RFS) in patients with an increased count of CD4+ and GATA3+ T-cells. TAMs, Tregs and T-bet+ T-cells were inversely correlated with RFS. Thus, the tumor microenvironment seems to influence the therapeutic response to BCG, permitting an individualized treatment.

CD8+CD28-CD127loCD39+ regulatory T-cell expansion: A new possible pathogenic mechanism for HIV infection?

BACKGROUND

HIV-associated immunodeficiency is related to loss of CD4⁺ T cells. This mechanism does not explain certain manifestations of HIV disease, such as immunodeficiency events in patients with greater than 500 CD4⁺ T cells/μL. CD8⁺CD28^-CD127^loCD39⁺ T cells are regulatory T (Treg) lymphocytes that are highly concentrated within the tumor microenvironment and never analyzed in the circulation of HIV-infected patients.

OBJECTIVES

We sought to analyze the frequency of CD8⁺CD28^-CD127^loCD39⁺ Treg cells in the circulation of HIV-infected patients.

METHODS

The frequency of circulating CD8⁺CD28^-CD127^loCD39⁺ Treg cells was analyzed and correlated with viral load and CD4⁺ T-cell counts/percentages in 93 HIV-1-infected patients subdivided as follows: naive (n = 63), elite controllers (n = 19), long-term nonprogressors (n = 7), and HIV-infected patients affected by tumor (n = 4). The same analyses were performed in HIV-negative patients with cancer (n = 53), hepatitis C virus-infected patients (n = 17), and healthy donors (n = 173).

RESULTS

HIV-infected patients had increased circulating levels of functional CD8⁺CD28^-CD127^loCD39⁺ Treg cells. These cells showed antigen specificity against HIV proteins. Their frequency after antiretroviral therapy (ART) correlated with HIV viremia, CD4⁺ T-cell counts, and immune activation markers, suggesting their pathogenic involvement in AIDS- or non-AIDS-related complications. Their increase after initiation of ART heralded a lack of virologic or clinical response, and hence their monitoring is clinically relevant.

CONCLUSION

HIV infection induces remarkable expansion of CD8⁺CD28^-CD127^loCD39⁺ Treg cells, the frequency of which correlates with both clinical disease and signs of chronic immune cell activation. Monitoring their frequency in the circulation is a new marker of response to ART when effects on viremia and clinical response are not met.

Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

The immune infiltrate in prostate, bladder and testicular tumors: An old friend for new challenges

In genito-urinary tumors immunotherapy has been administered for a long time: Calmette-Guèrin Bacillus as adjuvant treatment in high risk patients with non muscle invasive urothelial bladder cancer and interleukin-2 and interferon-α in metastatic kidney cancer. The vaccine Sipuleucel-T has been approved by United States Food and Drug Administration for the treatment of castration resistant prostate cancer patients with asymptomatic or minimally symptomatic disease, given the 22% reduction of mortality risk in this group. Recently immunotherapeutic agents targeting inhibitory immune checkpoint molecules lead to improved outcomes and lasting anti-tumor effects in a variety of hematological and solid malignancies, including urogenital tumors. The benefit from these treatments has been observed only in a proportion of subjects, raising a need in optimizing patients' selection for immune checkpoint blockade. The composition and activity of a pre-existing immune infiltrate may aid in identifying ideal candidates to immunotherapy, with possible implications for the clinical management of neoplastic diseases from earlier to later stages.

Cathepsin S inhibition changes regulatory T-cell activity in regulating bladder cancer and immune cell proliferation and apoptosis

Regulatory T cells (Tregs) are immune suppressive cells, but their roles in tumor growth have been elusive, depending on tumor type or site. Our prior study demonstrated a role of cathepsin S (CatS) in reducing Treg immunosuppressive activity. Therefore, CatS inhibition in Tregs may exacerbate tumor growth. Using mouse bladder carcinoma MB49 cell subcutaneous implant tumor model, we detected no difference in tumor growth, whether mice were given saline- or CatS inhibitor-treated Tregs. However, mice that received inhibitor-treated Tregs had fewer splenic and tumor Tregs, and lower levels of tumor and splenic cell proliferation than mice that received saline-treated Tregs. In vitro, inhibitor-treated Tregs showed lower proliferation and higher apoptosis than saline-treated Tregs when cells were exposed to MB49. In contrast, both types of Tregs showed no difference in proliferation when they were co-cultured with normal splenocytes. Inhibitor-treated Tregs had less apoptosis in splenocytes, but more apoptosis in splenocytes with MB49 conditioned media than saline-treated Tregs. In turn, we detected less proliferation and more apoptosis of MB94 cells after co-culture with inhibitor-treated Tregs, compared with saline-treated Tregs. B220⁺ B-cell, CD4⁺ T-cell, and CD8⁺ T-cell proliferation and apoptosis were also lower in splenocytes co-cultured with inhibitor-treated Tregs than with saline-treated Tregs. Under the same conditions, the addition of cancer cell-conditioned media greatly increased CD8⁺ T-cell proliferation and reduced CD8⁺ T-cell apoptosis. These observations suggest that CatS inhibition of Tregs may reduce overall T-cell immunity under normal conditions, but enhance CD8⁺ T-cell immunity in the presence of cancer cells.

Clinical significance of T-bet, GATA-3, and Bcl-6 transcription factor expression in bladder carcinoma

Background

The aim of this study was to investigate the clinical significance of three immune cell-related transcription factors, T-bet, GATA-3 and Bcl-6 in bladder cancer in Tunisian patients.

Methods

Expression of T-bet, GATA-3 and Bcl-6 genes was assessed using RT-qPCR in 65 bladder cancers from patients: 32 being diagnosed as low- and medium-grade, 31 as high-grade, 25 as muscle invasive stage and 39 as non-muscle invasive stage. Gene expression was statistically correlated according to the grade, the stage, tobacco consumption, the BCG response and disease severity.

Results

T-bet levels in patients with high-grade bladder cancer were significantly elevated compared to patients with low- or medium-grade bladder cancer (p = 0.005). In invasive carcinoma (T2–T4), the T-bet levels were significantly higher than in superficial non-invasive bladder tumors (Tis, Ta, and T1) (p = 0.02). However, T-bet is predictive of the response to BCG. Its expression is high in good responders to BCG (p = 0.02). In contrast, the expression of GATA-3 and Bcl-6 in non-invasive carcinoma (p = 0.008 and p = 0.0003) and in patients with low- and medium-grade cancers (p = 0.001 and p < 0.0001) is significantly higher than in invasive bladder tumors and in patients with high-grade bladder carcinoma, respectively. In addition, heavy smokers, whose tumors express low levels of GATA-3 and Bcl-6, are poor responders to BCG (p = 0.01 and p = 0.03). Finally, better patient survival correlated with GATA-3 (p = 0.04) and Bcl-6 (p = 0.04) but not T-bet expression.

Conclusions

Our results suggest that T-bet expression in bladder tumors could be a positive prognostic indicator of BCG therapy, even if high levels are found in high-grade and stage of the disease. However, GATA-3 and Bcl-6 expression could be considered as predictive factors for good patient survival.