Harnessing the potential of CAR-T cell therapy: progress, challenges, and future directions in hematological and solid tumor treatments.

Traditional cancer treatments use nonspecific drugs and monoclonal antibodies to target tumor cells. Chimeric antigen receptor (CAR)-T cell therapy, however, leverages the immune system's T-cells to recognize and attack tumor cells. T-cells are isolated from patients and modified to target tumor-associated antigens. CAR-T therapy has achieved FDA approval for treating blood cancers like B-cell acute lymphoblastic leukemia, large B-cell lymphoma, and multiple myeloma by targeting CD-19 and B-cell maturation antigens. Bi-specific chimeric antigen receptors may contribute to mitigating tumor antigen escape, but their efficacy could be limited in cases where certain tumor cells do not express the targeted antigens. Despite success in blood cancers, CAR-T technology faces challenges in solid tumors, including lack of reliable tumor-associated antigens, hypoxic cores, immunosuppressive tumor environments, enhanced reactive oxygen species, and decreased T-cell infiltration. To overcome these challenges, current research aims to identify reliable tumor-associated antigens and develop cost-effective, tumor microenvironment-specific CAR-T cells. This review covers the evolution of CAR-T therapy against various tumors, including hematological and solid tumors, highlights challenges faced by CAR-T cell therapy, and suggests strategies to overcome these obstacles, such as utilizing single-cell RNA sequencing and artificial intelligence to optimize clinical-grade CAR-T cells.

Ubiquitin specific peptidase 37 and PCNA interaction promotes osteosarcoma pathogenesis by modulating replication fork progression.

BACKGROUND: Osteosarcoma is a type of bone cancer that predominantly affects young individuals, including children and adolescents. The disease progresses through heterogeneous genetic alterations, and patients often develop pulmonary metastases even after the primary tumors have been surgically removed. Ubiquitin-specific peptidases (USPs) regulate several critical cellular processes, such as cell cycle progression, transcriptional activation, and signal transduction. Various studies have revealed the significance of USP37 in the regulation of replication stress and oncogenesis. METHODS: In this study, the Cancer Genome Atlas (TCGA) database was analyzed to investigate USP37 expression. RNA sequencing was utilized to assess the impact of USP37 overexpression and depletion on gene expression in osteosarcoma cells. Various molecular assays, including colony formation, immunofluorescence, immunoprecipitation, and DNA replication restart, were employed to examine the physical interaction between USP37 and PCNA, as well as its physiological effects in osteosarcoma cells. Additionally, molecular docking studies were conducted to gain insight into the nature of the interaction between USP37 and PCNA. Furthermore, immunohistochemistry was performed on archived tissue blocks from osteosarcoma patients to establish a correlation between USP37 and PCNA expression. RESULTS: Analysis of the TCGA database revealed that increased expression of USP37 was linked to decreased progression-free survival (PFS) in osteosarcoma patients. Next-generation sequencing analysis of osteosarcoma cells demonstrated that overexpression or knockdown of USP37 led to the expression of different sets of genes. USP37 overexpression provided a survival advantage, while its depletion heightened sensitivity to replication stress in osteosarcoma cells. USP37 was found to physically interact with PCNA, and molecular docking studies indicated that the interaction occurs through unique residues. In response to genotoxic stress, cells that overexpressed USP37 resolved DNA damage foci more quickly than control cells or cells in which USP37 was depleted. The expression of USP37 varied in archived osteosarcoma tissues, with intermediate expression seen in 52% of cases in the cohort examined. CONCLUSION: The results of this investigation propose that USP37 plays a vital role in promoting replication stress tolerance in osteosarcoma cells. The interaction between USP37 and PCNA is involved in the regulation of replication stress, and disrupting it could potentially trigger synthetic lethality in osteosarcoma. This study has expanded our knowledge of the mechanism through which USP37 regulates replication stress, and its potential as a therapeutic target in osteosarcoma merits additional exploration.

Phosphorylation of HSP90 by protein kinase A is essential for the nuclear translocation of androgen receptor.

The androgen receptor (AR) is often activated in prostate cancer patients undergoing androgen-ablative therapy because of the activation of cellular pathways that stimulate the AR despite low androgen levels. In many of these tumors, the cAMP-dependent protein kinase A (PKA) pathway is activated. Previous studies have shown that PKA can synergize with low levels of androgen to enhance androgen signaling and consequent cell proliferation, leading to castration-resistant prostate cancer. However, the mechanism by which PKA causes AR stimulation in the presence of low/no androgen is not established yet. Here, using immunofluorescence immunoblotting assays, co-immunoprecipitation, siRNA-mediated gene silencing, and reporter gene assays, we demonstrate that PKA activation is necessary for the phosphorylation of heat shock protein (HSP90) that binds to unliganded AR in the cytoplasm, restricting its entry into the nucleus. We also found that PKA-mediated phosphorylation of the Thr89 residue in HSP90 releases AR from HSP90, enabling AR binding to HSP27 and its migration into the nucleus. Substitution of the Thr89 in HSP90 prevented its phosphorylation by PKA and significantly reduced AR transactivation and cellular proliferation. We further observed that the transcription of AR target genes, such as prostate-specific antigen (PSA), is also lowered in the HSP90 Thr89 variant. These results suggest that using a small-molecule inhibitor against the HSP90 Thr89 residue in conjunction with existing androgen-ablative therapy may be more effective than androgen-ablative therapy alone in the treatment of prostate cancer patients.

CAR-T cell therapy: a game-changer in cancer treatment and beyond.

In recent years, cancer has become one of the primary causes of mortality, approximately 10 million deaths worldwide each year. The most advanced, chimeric antigen receptor (CAR) T cell immunotherapy has turned out as a promising treatment for cancer. CAR-T cell therapy involves the genetic modification of T cells obtained from the patient's blood, and infusion back to the patients. CAR-T cell immunotherapy has led to a significant improvement in the remission rates of hematological cancers. CAR-T cell therapy presently limited to hematological cancers, there are ongoing efforts to develop additional CAR constructs such as bispecific CAR, tandem CAR, inhibitory CAR, combined antigens, CRISPR gene-editing, and nanoparticle delivery. With these advancements, CAR-T cell therapy holds promise concerning potential to improve upon traditional cancer treatments such as chemotherapy and radiation while reducing associated toxicities. This review covers recent advances and advantages of CAR-T cell immunotherapy.

Ubiquitination and deubiquitination: Implications on cancer therapy.

The ubiquitin proteasomal system (UPS) represents a highly regulated protein degradation pathway essential for maintaining cellular homeostasis. This system plays a critical role in several cellular processes, which include DNA damage repair, cell cycle checkpoint control, and immune response regulation. Recently, the UPS has emerged as a promising target for cancer therapeutics due to its involvement in oncogenesis and tumor progression. Here we aim to summarize the key aspects of the UPS and its significance in cancer therapeutics. We begin by elucidating the fundamental components of the UPS, highlighting the role of ubiquitin, E1-E3 ligases, and the proteasome in protein degradation. Furthermore, we discuss the intricate process of ubiquitination and proteasomal degradation, emphasizing the specificity and selectivity achieved through various signaling pathways. The dysregulation of the UPS has been implicated in cancer development and progression. Aberrant ubiquitin-mediated degradation of key regulatory proteins, such as tumor suppressors and oncoproteins, can lead to uncontrolled cell proliferation, evasion of apoptosis, and metastasis. We outline the pivotal role of the UPS in modulating crucial oncogenic pathways, including the regulation of cyclins, transcription factors, Replication stress components and DNA damage response. The increasing recognition of the UPS as a target for cancer therapeutics has spurred the development of small molecules, peptides, and proteasome inhibitors with the potential to restore cellular balance and disrupt tumor growth. We provide an overview of current therapeutic strategies aimed at exploiting the UPS, including the use of proteasome inhibitors, deubiquitinating enzyme inhibitors, and novel E3 ligase modulators. We further discuss novel emerging strategies for the development of next-generation drugs that target proteasome inhibitors. Exploiting the UPS for cancer therapeutics offers promising avenues for developing innovative and effective treatment strategies, providing hope for improved patient outcomes in the fight against cancer.

Cyclin-dependent kinases in cancer: Role, regulation, and therapeutic targeting.

Regulated cell division is one of the fundamental phenomena which is the basis of all life on earth. Even a single base pair mutation in DNA leads to the production of the dysregulated protein that can have catastrophic consequences. Cell division is tightly controlled and orchestrated by proteins called cyclins and cyclin-dependent kinase (CDKs), which serve as licensing factors during different phases of cell division. Dysregulated cell division is one of the most important hallmarks of cancer and is commonly associated with a mutation in cyclins and CDKs along with tumor suppressor proteins. Therefore, targeting the component of the cell cycle which leads to these characteristics would be an effective strategy for treating cancers. Specifically, Cyclin-dependent kinases (CDKs) involved in cell cycle regulation have been identified to be overexpressed in many cancers. Many studies indicate that oncogenesis occurs in cancerous cells by the overactivity of different CDKs, which impact cell cycle progression and checkpoint dysregulation which is responsible for development of tumor. The development of CDK inhibitors has emerged as a promising and novel approach for cancer treatment in both solid and hematological malignancies. Some of the novel CDK inhibitors have shown remarkable results in clinical trials, such as-Ribociclib®, Palbociclib® and Abemaciclib®, which are CDK4/6 inhibitors and have received FDA approval for the treatment of breast cancer. In this chapter, we discuss the molecular mechanism through which cyclins and CDKs regulate cell cycle progression and the emergence of cyclins and CDKs as rational targets in cancer. We also discuss recent advances in developing CDK inhibitors, which have emerged as a novel class of inhibitors, and their associated toxicities in recent years.

CAR-T-Cell Therapy in Multiple Myeloma: B-Cell Maturation Antigen (BCMA) and Beyond.

Significant progress has been achieved in the realm of therapeutic interventions for multiple myeloma (MM), leading to transformative shifts in its clinical management. While conventional modalities such as surgery, radiotherapy, and chemotherapy have improved the clinical outcomes, the overarching challenge of effecting a comprehensive cure for patients afflicted with relapsed and refractory MM (RRMM) endures. Notably, adoptive cellular therapy, especially chimeric antigen receptor T-cell (CAR-T) therapy, has exhibited efficacy in patients with refractory or resistant B-cell malignancies and is now also being tested in patients with MM. Within this context, the B-cell maturation antigen (BCMA) has emerged as a promising candidate for CAR-T-cell antigen targeting in MM. Alternative targets include SLAMF7, CD38, CD19, the signaling lymphocyte activation molecule CS1, NKG2D, and CD138. Numerous clinical studies have demonstrated the clinical efficacy of these CAR-T-cell therapies, although longitudinal follow-up reveals some degree of antigenic escape. The widespread implementation of CAR-T-cell therapy is encumbered by several barriers, including antigenic evasion, uneven intratumoral infiltration in solid cancers, cytokine release syndrome, neurotoxicity, logistical implementation, and financial burden. This article provides an overview of CAR-T-cell therapy in MM and the utilization of BCMA as the target antigen, as well as an overview of other potential target moieties.

Novel use of coactivators to enhance sensitivity of SEAP-based reporter assay system for visual monitoring and quantitation of androgens and antiandrogens in water.

Every year thousands of chemicals get discharged into the waterbodies of the world. These chemicals cause endocrine disruption and induce adverse health effects in human and aquatic life. Global environmental protection agencies emphasise the need to develop rapid and specific tests for identification of these endocrine disruptive chemicals (EDCs) in water. Detection of chemicals that disrupt androgen signaling is especially important because androgen input at specific phases of life is critical for proper male development. Effect-based methods such as reporter assays are suitable tools for identification of EDCs in mixtures of unknown composition. The current study describes a stable, secreted alkaline protease (SEAP)-based reporter assay system, for visual detection of androgenic/antiandrogenic activity present in water samples. A novel feature of this system is the inclusion of coactivators, GRIP1, CARM1, p300 and mZac1b, in addition to an optimal combination of androgen response element (3× HRE), androgen receptor (AR) and the SEAP reporter gene. Incorporation of the coactivators resulted in a transcriptional fold change of 162 folds, enabling visual detection at much lower concentrations of androgen (1 picomolar) within 1 h of addition of test sample. Also, non-androgenic steroids such as estrogen, progesterone and Dexamethasone did not induce significant reporter activity, except at very high concentrations. This reporter assay can be readily converted into a high throughput format for investigation in multiple samples simultaneously, and reflects the changes that can be expected to occur inside a mammalian cell. The androgenic activity in six different water sources was evaluated using this assay. The results reveal significant androgenic activity in rivers and lakes close to Industrial areas, whereas the highest androgenic activity was observed in water containing paper and pulp mill effluents. This bioassay therefore provides a rapid, visual detection tool for effect-directed analysis of androgenic/antiandrogenic compounds in water. IMPACT STATEMENT: The current SEAP-based assay allows visual detection of androgens/antiandrogens in water, at concentrations as low as 1 picomolar, within a 1 h time period, in a high throughput format, providing a very useful technique for field users and regulatory bodies.

Activation of GPR56, a novel adhesion GPCR, is necessary for nuclear androgen receptor signaling in prostate cells.

The androgen receptor (AR) is activated in patients with castration resistant prostate cancer (CRPC) despite low circulating levels of androgen, suggesting that intracellular signaling pathways and non-androgenic factors may contribute to AR activation. Many G-protein coupled receptors (GPCR) and their ligands are also activated in these cells indicating that they may play a role in development of Prostate Cancer (PCa) and CRPC. Although a cross talk has been suggested between the two pathways, yet, the identity of GPCRs which may play a role in androgen signaling, is not established yet. By using blast analysis of 826 GPCRs, we identified a GPCR, GPCR 205, which exhibited maximum similarity with the ligand binding domain of the AR. We demonstrate that adhesion GPCR 205, also known as GPR56, can be activated by androgens to stimulate the Rho signaling pathway, a pathway that plays an important role in prostate tumor cell metastasis. Testosterone stimulation of GPR56 also activates the cAMP/ Protein kinase A (PKA) pathway, that is necessary for AR signaling. Knocking down the expression of GPR56 using siRNA, disrupts nuclear translocation of AR and transcription of prototypic AR target genes such as PSA. GPR56 expression is higher in all twenty-five prostate tumor patient's samples tested and cells expressing GPR56 exhibit increased proliferation. These findings provide new insights about androgen signaling and identify GPR56 as a possible therapeutic target in advanced prostate cancer patients.