Specific subsets of urothelial bladder carcinoma infiltrating T cells associated with poor prognosis.

Comprehensive investigation of tumor-infiltrating lymphocytes in cancer is crucial to explore the effective immunotherapies, but the composition of infiltrating T cells in urothelial bladder carcinoma (UBC) remains elusive. Here, single-cell RNA sequencing (scRNA-seq) were performed on total 30,905 T cells derived from peripheral blood, adjacent normal and tumor tissues from two UBC patients. We identified 18 distinct T cell subsets based on molecular profiles and functional properties. Specifically, exhausted T (TEx) cells, exhausted NKT (NKTEx) cells, Ki67+ T cells and B cell-like T (B-T) cells were exclusively enriched in UBC. Additionally, the gene signatures of TEx, NKTEx, Ki67+ T and B-T cells were significantly associated with poor survival in patients with BC and various tumor types. Finally, IKZF3 and TRGC2 are the potential biomarkers of TEx cells. Overall, our study demonstrated an exhausted context of T cells in UBC, which layed a theoretical foundation for the development of effective tumor immunotherapies.

Immune escape mechanisms and immunotherapy of urothelial bladder cancer.

BACKGROUND AND AIM: Urothelial bladder cancer (UBC) is a common malignant tumor of the urogenital system with a high rate of recurrence. Due to the sophisticated and largely unexplored mechanisms of tumorigenesis of UBC, the classical therapeutic approaches including transurethral resection and radical cystectomy combined with chemotherapy have remained unchanged for decades. However, with increasingly in-depth understanding of the microenvironment and the composition of tumor-infiltrating lymphocytes of UBC, novel immunotherapeutic strategies have been developed. Bacillus Calmette-Guerin (BCG) therapy, immune checkpoint blockades, adoptive T cell immunotherapy, dendritic cell (DC) vaccines, etc., have all been intensively investigated as immunotherapies for UBC. This review will discuss the recent progress in immune escape mechanisms and immunotherapy of UBC. METHODS: Based on a comprehensive search of the PubMed and ClinicalTrials.gov database, this review included the literature reporting the immune escape mechanisms of UBC and clinical trials assessing the effect of immunotherapeutic strategies on tumor or immune cells in UBC patients published in English between 1999 and 2020. RESULTS: Immune surveillance, immune balance, and immune escape are the three major processes that occur during UBC tumorigenesis. First, the role of immunosuppressive cells, immunosuppressive molecules, immunosuppressive signaling molecules, and DCs in tumor microenvironment is introduced elaborately in the immune escape mechanisms of UBC section. In addition, recent progress of immunotherapies including BCG, checkpoint inhibitors, cytokines, adoptive T cell immunotherapy, DCs, and macrophages on UBC patients are summarized in detail. Finally, the need to explore the mechanisms, molecular characteristics and immune landscape during UBC tumorigenesis and development of novel and robust immunotherapies for UBC are also proposed and discussed. CONCLUSION: At present, BCG and immune checkpoint blockades have been approved by the US Food and Drug Administration for the treatment of UBC patients and have achieved encouraging therapeutic results, expanding the traditional chemotherapy and surgery-based treatment for UBC. RELEVANCE FOR PATIENTS: Immunotherapy has achieved desirable results in the treatment of UBC, which not only improve the overall survival but also reduce the recurrence rate and the occurrence of treatment-related adverse events of UBC patients. In addition, the indicators to predict the effectiveness and novel therapy strategies, such as combination regimen of checkpoint inhibitor with checkpoint inhibitor or chemotherapy, should be further studied.

[Molecular markers and mechanisms for stemness maintenance of liver cancer stem cells: a review].

Primary liver cancer (PLC) is an aggressive tumor and prone to metastasize and recur. According to pathological features, PLC are mainly categorized into hepatocellular carcinoma, intrahepatic cholangiocarcinoma, mixed hepatocellular cholangiocarcinoma, and fibrolamelic hepatocellular carcinoma, etc. At present, surgical resection, radiotherapy and chemotherapy are still the main treatments for PLC, but the specificities are poor and the clinical effects are limited with a 5-year overall survival rate of 18%. Liver cancer stem cells (LCSCs) are a specific cell subset existing in liver cancer tissues. They harbor the capabilities of self-renewal and strong tumorigenicity, driving tumor initiation, metastasis, drug resistance and recurrence of PLC. Therefore, the identification of molecular markers and the illustration of mechanisms for stemness maintenance of LCSCs can not only reveal the molecular mechanisms of PLC tumorigenesis, but also lay a theoretical foundation for the molecular classification, prognosis evaluation and targeted therapy of PLC. The latest research showed that the combination of 5-fluorouracil and CD13 inhibitors could inhibit the proliferation of CD13+ LCSCs, thereby reducing overall tumor burden. Taken together, LCSCs could be the promising therapeutic targets of PLC in the future. This review summarizes the latest progress in molecular markers, mechanisms for stemness maintenance and targeted therapies of LCSCs.

[Bispecific antibodies in clinical tumor therapy].

Bispecific antibody (BsAb) has two different antigen-binding sites, divided into the "IgG-like" format and the "non-IgG-like" format. Different formats have different characteristics and applications. BsAb has higher sensitivity and specificity than conventional antibodies, with special functions such as recruitment of immune cells and blocking of dual signaling pathways, playing an important role in immune-diagnosis and therapy. With the deterioration of the global environment and the irregular living habits of people, the incidence of tumor is becoming higher and higher. Tumor becomes the most serious fatal disease threatening human health after cardiovascular disease. There are 12 million estimated new tumor cases each year worldwide. The major clinical treatments of tumor are surgical resection, chemoradiotherapy, target therapy. Tumor immunotherapy is a novel approach for tumor treatment in recent years, and activates human immune system to control and kill tumor cells. Although the traditional monoclonal antibodies have already acquired some therapeutic effects in tumor targeted therapy and immunotherapy, they induce drug resistance resulted from the heterogeneity and plasticity of tumors. Binding to two target antigens at the same time, BsAb has been used in the clinical treatment of tumors and obtained promising outcomes. This review elaborates the research progress and applications of bispecific antibody in clinical tumor therapy.

[Function of tumor infiltrating lymphocytes in solid tumors - a review].

Tumor is one of the major diseases threatening human health in the 21st century. Surgical resection, radiotherapy, chemotherapy and targeted therapy are the main clinical treatments for solid tumors. However, these methods are unable to eradicate tumor cells completely, and easily lead to the recurrence and progression of tumor. Tumor immunotherapy is a novel treatment that uses human immune system to control and kill tumor by enhancing or restoring anti-tumor immunity. Tumor immunotherapy has shown to produce long-lasting responses in large numbers of patients, and thereby adoptive immunotherapy and immune checkpoint inhibitors could induce remarkable antigen-specific immune responses. Tumor infiltrating lymphocytes (TILs) are highly heterogeneous lymphocytes existing in tumor tissues and play a crucial role in host antigen-specific tumor immune response. Recent studies show that TILs are closely related to the prognosis of patients during the processes of tumorigenesis and treatment. Adoptive immunotherapy mediated by TILs has displayed favorable curative effect in many solid tumors. This paper reviews the recent progress of TILs in solid tumors.

[Progress in immunotherapy for hepatocellular carcinoma].

Hepatocellular carcinoma (HCC) is one of the malignant tumors with the highest morbidity and mortality in the world. The morbidity and mortality of HCC are increasing every year. Liver cancer is a serious threat to public health in China and the death rate of patients with liver cancer in China is the highest in the world. Beyond surgery, chemotherapy and radiotherapy, immunotherapy is an emerging treatment for cancer, which could control and kill tumor cells by relieving the inhibitory status of immune cells in the tumor microenvironment and activating the immune function of the body. Immune checkpoint inhibitors, adoptive immunotherapy and tumor vaccine are the major treatments of immunotherapy. Compared with traditional therapy methods, immunotherapy could enhance immune function, delay tumor progression, prolong the survival time of patients, and becomes a hotspot in the basic and clinical cancer research. This article reviews the research progress of immunotherapy for liver cancer.