EpCAM-targeting CAR-T cell immunotherapy is safe and efficacious for epithelial tumors

The potential application of stroma modulation in targeting tumor cells: focus on pancreatic cancer and breast cancer models

The tumor microenvironment (TME) plays a crucial role in cancer development and spreading being considered as "the dark side of the tumor". Within this term tumor cells, immune components, supporting cells, extracellular matrix and a myriad of bioactive molecules that synergistically promote tumor development and therapeutic resistance, are included. Recent findings revealed the profound impacts of TME on cancer development, serving as physical support, critical mediator and biodynamic matrix in cancer evolution, immune modulation, and treatment outcomes. TME targeting strategies built on vasculature, immune checkpoints, and immuno-cell therapies, have paved the way for revolutionary clinical interventions. On this basis, the relevance of pre-clinical and clinical investigations has rapidly become fundamental for implementing novel therapeutical strategies breaking cell-cell and cell -mediators' interactions between TME components and tumor cells. This review summarizes the key players in the breast and pancreatic TME, elucidating the intricate interactions among cancer cells and their essential role for cancer progression and therapeutic resistance. Different tumors such breast and pancreatic cancer have both different and similar stroma features, that might affect therapeutic strategies. Therefore, this review aims to comprehensively evaluate recent findings for refining breast and pancreatic cancer therapies and improve patient prognoses by exploiting the TME's complexity in the next future.

Viral oncogenesis in cancer: from mechanisms to therapeutics

The year 2024 marks the 60th anniversary of the discovery of the Epstein-Barr virus (EBV), the first virus confirmed to cause human cancer. Viral infections significantly contribute to the global cancer burden, with seven known Group 1 oncogenic viruses, including hepatitis B virus (HBV), human papillomavirus (HPV), EBV, Kaposi sarcoma-associated herpesvirus (KSHV), hepatitis C virus (HCV), human T-cell leukemia virus type 1 (HTLV-1), and human immunodeficiency virus (HIV). These oncogenic viruses induce cellular transformation and cancer development by altering various biological processes within host cells, particularly under immunosuppression or co-carcinogenic exposures. These viruses are primarily associated with hepatocellular carcinoma, gastric cancer, cervical cancer, nasopharyngeal carcinoma, Kaposi sarcoma, lymphoma, and adult T-cell leukemia/lymphoma. Understanding the mechanisms of viral oncogenesis is crucial for identifying and characterizing the early biological processes of virus-related cancers, providing new targets and strategies for treatment or prevention. This review first outlines the global epidemiology of virus-related tumors, milestone events in research, and the process by which oncogenic viruses infect target cells. It then focuses on the molecular mechanisms by which these viruses induce tumors directly or indirectly, including the regulation of oncogenes or tumor suppressor genes, induction of genomic instability, disruption of regular life cycle of cells, immune suppression, chronic inflammation, and inducing angiogenesis. Finally, current therapeutic strategies for virus-related tumors and recent advances in preclinical and clinical research are discussed.

CAR T cells in lung cancer: Targeting tumor-associated antigens to revolutionize immunotherapy

Tumor-targeted T cells engineered for targeting and killing tumor cells have revolutionized cancer treatment, specifically in hematologic malignancies, through chimeric antigen receptor (CAR) T cell therapy. However, the migration of this success to lung cancer is challenging due to the tumor microenvironment (TME), antigen heterogeneity, and limitations of T cell infiltration. This review aims to evaluate current strategies addressing these barriers, focusing on the optimization of tumor-associated antigen (TAA) targeting, such as epidermal growth factor receptor (EGFR), mucin-1 (MUC1), and mesothelin (MSLN), which are frequently overexpressed in lung cancer and offer promising targets for CAR T-cell therapy. In this review, we discuss recent progress in CAR T cell engineering, applying enhanced costimulatory molecules, cytokine-secreting CAR T cells, and engineered modifications to improve T cell resilience in immunosuppressive environments. Additionally, this review also evaluates combination therapies of immune checkpoint inhibitors and recently published clinical trials on lung cancer with CAR T cells. We offer insights into the way to optimize CAR T cell therapy for lung cancer by analyzing antigen selection, immune evasion, and the strategies to enhance T cell persistence and tumor infiltration.

Tailoring CAR surface density and dynamics to improve CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment landscape for relapsed and/or refractory B-cell neoplasms, garnering Food and Drug Administration/European Medicines Agency approval for six commercial products. Despite this success, challenges persist, including a relapse rate of 30-50% in hematologic tumors, limited clinical efficacy in solid tumors, and severe side effects. This review addresses the critical need for therapeutic enhancement by focusing on the often-overlooked strategy of modulating CAR protein density on the cell membrane. We delve into the key factors influencing CAR surface expression, such as CAR downmodulation following antigen encounter and antigen-related factors. The dynamics of CAR downmodulation remain underexplored; however, recent data point to its modification as a useful tool for improving functionality. Notably, transcriptional control of CAR expression and the incorporation of specific elements into the CAR design have emerged as interesting strategies to tailor CAR expression profiles. Therefore, controlling CAR dynamic density may represent an attractive strategy for achieving optimal therapeutic outcomes.

Stem Cells in Cancer: From Mechanisms to Therapeutic Strategies

Stem cells have emerged as a pivotal area of research in the field of oncology, offering new insights into the mechanisms of cancer initiation, progression, and resistance to therapy. This review provides a comprehensive overview of the role of stem cells in cancer, focusing on cancer stem cells (CSCs), their characteristics, and their implications for cancer therapy. We discuss the origin and identification of CSCs, their role in tumorigenesis, metastasis, and drug resistance, and the potential therapeutic strategies targeting CSCs. Additionally, we explore the use of normal stem cells in cancer therapy, focusing on their role in tissue regeneration and their use as delivery vehicles for anticancer agents. Finally, we highlight the challenges and future directions in stem cell research in cancer.

ZP4: A novel target for CAR-T cell therapy in triple negative breast cancer

Triple-negative breast cancer (TNBC) remains one of the most challenging subtypes of breast cancer to treat due to a lack of effective targeted therapies. Chimeric antigen receptor (CAR)-T cells hold promise, but their efficacy in solid tumors is often limited by on-target/off-tumor toxicities. Through comprehensive bioinformatic analysis of public RNA and proteomic data, we identified zona pellucida glycoprotein 4 (ZP4) as a novel target for TNBC. ZP4 RNA and protein were detected in a subset of TNBC patient samples and patient-derived xenograft (PDX) models, with expression otherwise restricted to oocytes. We generated 89 ZP4-specific novel monoclonal antibodies and used the single-chain variable fragment (scFv) antigen binding domains from the top three candidates to engineer CAR constructs. ZP4 CAR-T cells demonstrated efficacy against ZP4-expressing TNBC cells and PDX models. Additionally, we found that variations in the scFv antigen binding domain significantly influence CAR-T cell function.

Transforming Growth Factor Beta2 Promotes Migration and Inhibits the Proliferation of Gastric Cancer Cells by Regulating the pSmad2/3-NDRG1 Signaling Pathway

Transforming growth factor beta2 (TGFβ2) is upregulated in gastric cancer (GC), playing a crucial role in driving its progression. However, the biological effects of TGFβ2 in GC metastasis and proliferation remain not fully understood. Our study reveals that TGFβ2 enhances N-myc downstream-regulated gene 1 (NDRG1) protein expression by activating the TGFβR/Smad2/3-dependent pathway, accelerating GC progression. TGFβ2 knockdown downregulates NDRG1 by inhibiting the TGFβR/Smad2/3 signaling pathway, which in turn inhibits GC cell migration and epithelial-mesenchymal transition (EMT) but stimulates proliferation. Both TGFβ2 upregulation and NDRG1 upregulation enhance GC cell migration in vitro and promote lung metastasis in mouse models. Interfering with NDRG1 reverses TGFβ2-induced migration, and inhibiting Smad2/3 or TGFβR reverses TGFβ2-induced NDRG1 upregulation and GC cell migration. Clinical sample analysis shows high TGFβ2 and NDRG1 expression in GC, associated with poor prognosis. Our study reveals that TGFβ2 upregulates NDRG1 via the TGFβR/Smad2/3 pathway, driving GC progression and highlighting the potential role of the TGFβ2NDRG1 axis in GC-targeted therapies.

Key immune cells and their crosstalk in the tumor microenvironment of bladder cancer: insights for innovative therapies

Bladder cancer (BC) is a heterogeneous disease associated with high mortality if not diagnosed early. BC is classified into non-muscle-invasive BC (NMIBC) and muscle-invasive BC (MIBC), with MIBC linked to poor systemic therapy response and high recurrence rates. Current treatments include transurethral resection with Bacillus Calmette-Guérin (BCG) therapy for NMIBC and radical cystectomy with chemotherapy and/or immunotherapy for MIBC. The tumor microenvironment (TME) plays a critical role in cancer progression, metastasis, and therapeutic efficacy. A comprehensive understanding of the TME's complex interactions holds substantial translational significance for developing innovative treatments. The TME can contribute to therapeutic resistance, particularly in immune checkpoint inhibitor (ICI) therapies, where resistance arises from tumor-intrinsic changes or extrinsic TME factors. Recent advancements in immunotherapy highlight the importance of translational research to address these challenges. Strategies to overcome resistance focus on remodeling the TME to transform immunologically "cold" tumors, which lack immune cell infiltration, into "hot" tumors that respond better to immunotherapy. These strategies involve disrupting cancer-microenvironment interactions, inhibiting angiogenesis, and modulating immune components to enhance anti-tumor responses. Key mechanisms include cytokine involvement [e.g., interleukin-6 (IL-6)], phenotypic alterations in macrophages and natural killer (NK) cells, and the plasticity of cancer-associated fibroblasts (CAFs). Identifying potential therapeutic targets within the TME can improve outcomes for MIBC patients. This review emphasizes the TME's complexity and its impact on guiding novel therapeutic approaches, offering hope for better survival in MIBC.

Biological roles and clinical applications of EpCAM in HCC

Epithelial cell adhesion molecule (EpCAM) is an important biomarker in tumors. In hepatocellular carcinoma (HCC), EpCAM + cells exhibit high invasiveness, tumorigenic ability, therapeutic resistance, and self-renewal ability, often identified as liver cancer stem cells (CSCs). Detecting EpCAM + cells in tumor lesions and circulation is valuable for predicting patient prognosis and monitoring therapeutic outcomes, emphasizing its clinical significance. Given its broad expression in HCC, especially in CSCs and circulating tumor cells (CTCs), EpCAM-targeting agents have garnered substantial research interest. However, the role of EpCAM in HCC progression and its regulatory mechanisms remains poorly understood. Furthermore, clinical applications of EpCAM, such as liquid biopsy and targeted therapies, are still controversial. This review summarizes the biological properties of EpCAM + HCC cells, explores the regulatory mechanisms governing EpCAM expression, and discusses its clinical significance of using EpCAM as a prognostic marker and therapeutic target.

Mechanisms and Strategies to Overcome Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide, with a significant impact on public health. Current treatment options include surgery, chemotherapy, radiotherapy, molecular-targeted therapy, and immunotherapy. Despite advancements in these therapeutic modalities, resistance remains a significant challenge, often leading to treatment failure, poor progression-free survival, and cancer recurrence. Mechanisms of resistance in CRC are multifaceted, involving genetic mutations, epigenetic alterations, tumor heterogeneity, and the tumor microenvironment. Understanding these mechanisms at the molecular level is crucial for identifying novel therapeutic targets and developing strategies to overcome resistance. This review provides an overview of the diverse mechanisms driving drug resistance in sporadic CRC and discusses strategies currently under investigation to counteract this resistance. Several promising strategies are being explored, including targeting drug transport, key signaling pathways, DNA damage response, cell death pathways, epigenetic modifications, cancer stem cells, and the tumor microenvironment. The integration of emerging therapeutic approaches that target resistance mechanisms aims to enhance the efficacy of current CRC treatments and improve patient outcomes.

EpCAM Signaling in Oral Cancer Stem Cells: Implications for Metastasis, Tumorigenicity, and Therapeutic Strategies

Oral cancer, a subtype of head and neck cancer, poses significant global health challenges owing to its late diagnosis and high metastatic potential. The epithelial cell adhesion molecule (EpCAM), a transmembrane glycoprotein, has emerged as a critical player in cancer biology, particularly in oral cancer stem cells (CSCs). This review highlights the multifaceted roles of EPCAM in regulating oral cancer metastasis, tumorigenicity, and resistance to therapy. EpCAM influences key pathways, including Wnt/β-catenin and EGFR, modulating CSC self-renewal, epithelial-to-mesenchymal transition (EMT), and immune evasion. Moreover, EpCAM has been implicated in metabolic reprogramming, epigenetic regulation, and crosstalk with other signaling pathways. Advances in EpCAM-targeting strategies, such as monoclonal antibodies, chimeric antigen receptor (CAR) T/NK cell therapies, and aptamer-based systems hold promise for personalized cancer therapies. However, challenges remain in understanding the precise mechanism of EpCAM in CSC biology and its translation into clinical applications. This review highlights the need for further investigation into the role of EPCAM in oral CSCs and its potential as a therapeutic target to improve patient outcomes.

Exploring CAR-PBMCs: A Novel Strategy Against EGFR-Positive Tumor Cells

Background: Chimeric antigen receptor (CAR) T cell therapy has shown significant promise in treating hematological malignancies, yet its application in solid tumors, particularly those expressing the epidermal growth factor receptor (EGFR), remains limited. This study investigates the potential of CAR-engineered peripheral blood mononuclear cells (PBMCs) as a novel adoptive cell therapy against EGFR-positive cancers. Methods: Lentiviral transduction at an MOI of 50 was performed to generate specific anti-EGFR second generation CAR-effector cells. The transduced PBMCs were stimulated with cytokines and CD3/CD28 beads to enhance their proliferation and activation. Flow cytometric and real-time cell analysis were performed at various effector-to-target ratios to explore the cytotoxic potential of CAR-PBMCs. Results: CAR-PBMCs exhibited improved targeting and cytotoxicity against EGFR-positive cancer cell lines MDA-MB-468 and SK-BR-3, compared to untransduced controls, with unsignificant effects on allogeneic PBMCs. Conclusion: CAR-PBMCs hold considerable potential as a therapeutic strategy for EGFR-positive solid tumors, warranting further clinical investigation.

Advances in CAR T cell therapy: antigen selection, modifications, and current trials for solid tumors

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of hematologic malignancies, achieving remarkable clinical success with FDA-approved therapies targeting CD19 and BCMA. However, the extension of these successes to solid tumors remains limited due to several intrinsic challenges, including antigen heterogeneity and immunosuppressive tumor microenvironments. In this review, we provide a comprehensive overview of recent advances in CAR T cell therapy aimed at overcoming these obstacles. We discuss the importance of antigen identification by emphasizing the identification of tumor-specific and tumor-associated antigens and the development of CAR T therapies targeting these antigens. Furthermore, we highlight key structural innovations, including cytokine-armored CARs, protease-regulated CARs, and CARs engineered with chemokine receptors, to enhance tumor infiltration and activity within the immunosuppressive microenvironment. Additionally, novel manufacturing approaches, such as the Sleeping Beauty transposon system, mRNA-based CAR transfection, and in vivo CAR T cell production, are discussed as scalable solution to improve the accessibility of CAR T cell therapies. Finally, we address critical therapeutic limitations, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and suboptimal persistence of CAR T cells. An examination of emerging strategies for countering these limitations reveals that CRISPR-Cas9-mediated genetic modifications and combination therapies utilizing checkpoint inhibitors can improve CAR T cell functionality and durability. By integrating insights from preclinical models, clinical trials, and innovative engineering approaches, this review addresses advances in CAR T cell therapies and their performance in solid tumors.

CAR-T cell therapy: Advances in digestive system malignant tumors

Malignant tumors of the digestive system have had a notoriously dismal prognosis throughout history. Immunotherapy, radiotherapy, surgery, and chemotherapy are the primary therapeutic approaches for digestive system cancers. The rate of recurrence and metastasis, nevertheless, remains elevated. As one of the immunotherapies, chimeric antigen receptor T cell (CAR-T) therapy has demonstrated a promising antitumor effect in hematologic cancer. Despite undergoing numerous clinical trials, the ineffective antitumor effect and adverse effects of CAR-T cell therapy in the treatment of digestive system cancers continue to impede its clinical translation. It is necessary to surmount the restricted options for targeting proteins, the obstacles that impede CAR-T cell infiltration into solid tumors, and the limited survival time in vivo. We examined and summarized the developments, obstacles, and countermeasures associated with CAR-T therapy in digestive system cancers. Emphasis was placed on the regulatory functions of potential antigen targets, the tumor microenvironment, and immune evasion in CAR-T therapy. Thus, our analysis has furnished an all-encompassing comprehension of CAR-T cell therapy in digestive system cancers, which will generate tremendous enthusiasm for subsequent in-depth research into CAR-T-based therapies in digestive system cancers.

Nanomaterial-based detection of circulating tumor cells and circulating cancer stem cells for cancer immunotherapy

Nanomaterials have emerged as transformative tools for detecting circulating tumor cells (CTCs) and circulating cancer stem cells (CCSCs), significantly enhancing cancer diagnostics and immunotherapy. Nanomaterials, including those composed of gold, magnetic materials, and silica, have enhanced the sensitivity, specificity, and efficiency of isolating these rare cells from blood. These developments are of paramount importance for the early detection of cancer and for providing real-time insights into metastasis and treatment resistance, which are essential for the development of personalized immunotherapies. The combination of nanomaterial-based platforms with phenotyping techniques, such as Raman spectroscopy and microfluidics, enables researchers to enhance immunotherapy protocols targeting specific CTC and CCSC markers. Nanomaterials also facilitate the targeted delivery of immunotherapeutic agents, including immune checkpoint inhibitors and therapeutic antibodies, directly to tumor cells. This synergistic approach has the potential to enhance therapeutic efficacy and mitigate the risk of metastasis and relapse. In conclusion, this review critically examines the use of nanomaterial-driven detection systems for detecting CTCs and CCSCs, their application in immunotherapy, and suggests future directions, highlighting their potential to transform the integration of diagnostics and treatment, thereby paving the way for more precise and personalized cancer therapies.

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.

Current biological implications and clinical relevance of metastatic circulating tumor cells

Metastatic disease and cancer recurrence are the primary causes of cancer-related deaths. Circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) are the driving forces behind the spread of cancer cells. The emergence and development of liquid biopsy using rare CTCs as a minimally invasive strategy for early-stage tumor detection and improved tumor management is a promising advancement in recent years. However, before blood sample analysis and clinical translation, precise isolation of CTCs from patients' blood based on their biophysical properties, followed by molecular identification of CTCs using single-cell multi-omics technologies is necessary to understand tumor heterogeneity and provide effective diagnosis and monitoring of cancer progression. Additionally, understanding the origin, morphological variation, and interaction between CTCs and the primary and metastatic tumor niche, as well as and regulatory immune cells, will offer new insights into the development of CTC-based advanced tumor targeting in the future clinical trials.

CAR-T cell therapy for hepatocellular carcinoma: current trends and challenges

Hepatocellular carcinoma (HCC) ranks among the most prevalent cancers worldwide, highlighting the urgent need for improved diagnostic and therapeutic methodologies. The standard treatment regimen generally involves surgical intervention followed by systemic therapies; however, the median survival rates for patients remain unsatisfactory. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a pivotal advancement in cancer treatment. Both clinical and preclinical studies emphasize the notable efficacy of CAR T cells in targeting HCC. Various molecules, such as GPC3, c-Met, and NKG2D, show significant promise as potential immunotherapeutic targets in liver cancer. Despite this, employing CAR T cells to treat solid tumors like HCC poses considerable challenges within the discipline. Numerous innovations have significant potential to enhance the efficacy of CAR T-cell therapy for HCC, including improvements in T cell trafficking, strategies to counteract the immunosuppressive tumor microenvironment, and enhanced safety protocols. Ongoing efforts to discover therapeutic targets for CAR T cells highlight the need for the development of more practical manufacturing strategies for CAR-modified cells. This review synthesizes recent findings and clinical advancements in the use of CAR T-cell therapies for HCC treatment. We elucidate the therapeutic benefits of CAR T cells in HCC and identify the primary barriers to their broader application. Our analysis aims to provide a comprehensive overview of the current status and future prospects of CAR T-cell immunotherapy for HCC.

In Silico Design of Novel EpCAM-Binding Aptamers for Targeted Delivery of RNA Therapeutics

Aptamers are short DNA or RNA sequences that adopt 3D structures and can bind to protein targets with high binding affinity and specificity. Aptamers exhibit excellent tissue penetration, are inexpensive to produce, and can be internalized by cells. Therefore, aptamers are attractive targeting ligands to direct the delivery of theranostic agents to the desired cells. Epithelial cell adhesion molecule (EpCAM) is a tumor-associated antigen that is aberrantly overexpressed on many epithelial-derived cancers, including on cholangiocarcinoma (CCA) cells. Its expression on treatment-resistant cancer stem cells, along with its abundance in the CCA tumor microenvironment, highlights the need to develop EpCAM-targeted therapies for CCA. Herein, an in silico approach was used to design and screen DNA aptamers capable of binding to the EpCAM monomer and homodimer. Two aptamers, PLD01 and PLD02, met the selection criteria and were validated in vitro. Both aptamers exhibited high affinity for EpCAM+ CCA cells, with negligible binding to EpCAM- leukemia cells. Modified versions of PLD01 and PLD02 were successfully incorporated into the membranes of milk-derived nanovesicles. PLD01-functionalized nanovesicles enabled EpCAM-targeted delivery of the therapeutic cargo to CCA cells. In summary, these EpCAM-targeting aptamers can be utilized to direct the delivery of theranostic agents to EpCAM-expressing cells.

Revolutionizing the treatment for nasopharyngeal cancer: the impact, challenges and strategies of stem cell and genetically engineered cell therapies

Nasopharyngeal carcinoma (NPC) is a distinct malignancy of the nasopharynx and is consistently associated with the Epstein-Barr virus (EBV) infection. Its unique anatomical location and complex aetiology often result in advanced-stage disease at first diagnosis. While radiotherapy (RT) and chemotherapy have been the mainstays of treatment, they often fail to prevent tumour recurrence and metastasis, leading to high rates of treatment failure and mortality. Recent advancement in cell-based therapies, such as chimeric antigen receptor (CAR)-T cell therapy, have shown great promise in hematological malignancies and are now being investigated for NPC. However, challenges such as targeting specific tumour antigens, limited T cell persistence and proliferation, and managing treatment-related toxicities must be addressed. Extensive research is needed to enhance the effectiveness and safety of these therapies, paving the way for their integration into standard clinical practice for better management of NPC and a better quality of life for human health.

Improving efficacy of TNBC immunotherapy: based on analysis and subtyping of immune microenvironment

Triple-negative breast cancer (TNBC) is a highly aggressive type of breast cancer that encompasses several distinct subtypes. Recent advances in immunotherapy offer a promising future for the treatment of these highly heterogeneous and readily metastatic tumors. Despite advancements, the efficacy of immunotherapy remains limited as shown by unimproved efficacy of PD-L1 biomarker and limited patient benefit. To enhance the effectiveness of TNBC immunotherapy, we conducted investigation on the microenvironment, and corresponding therapeutic interventions of TNBC and recommended further investigation into the identification of additional biomarkers that can facilitate the subtyping of TNBC for more targeted therapeutic approaches. TNBC is a highly aggressive subtype with dismal long-term survival due to the lack of opportunities for traditional endocrine and targeted therapies. Recent advances in immunotherapy have shown promise, but response rates can be limited due to the heterogeneous tumor microenvironments and developed therapy resistance, especially in metastatic cases. In this review, we will investigate the tumor microenvironment of TNBC and corresponding therapeutic interventions. We will summarize current subtyping strategies and available biomarkers for TNBC immunotherapy, with a particular emphasis on the need for further research to identify additional prognostic markers and refine tailored therapies for specific TNBC subtypes. These efforts aim to improve treatment sensitivity and ultimately enhance survival outcomes for advanced-stage TNBC patients.

PD-1 blockade does not improve efficacy of EpCAM-directed CAR T-cell in lung cancer brain metastasis

BACKGROUND

Lung cancer brain metastasis has a devastating prognosis, necessitating innovative treatment strategies. While chimeric antigen receptor (CAR) T-cell show promise in hematologic malignancies, their efficacy in solid tumors, including brain metastasis, is limited by the immunosuppressive tumor environment. The PD-L1/PD-1 pathway inhibits CAR T-cell activity in the tumor microenvironment, presenting a potential target to enhance therapeutic efficacy. This study aims to evaluate the impact of anti-PD-1 antibodies on CAR T-cell in treating lung cancer brain metastasis.

METHODS

We utilized a murine immunocompetent, syngeneic orthotopic cerebral metastasis model for repetitive intracerebral two-photon laser scanning microscopy, enabling in vivo characterization of red fluorescent tumor cells and CAR T-cell at a single-cell level over time. Red fluorescent EpCAM-transduced Lewis lung carcinoma cells (EpCAM/tdtLL/2 cells) were implanted intracranially. Following the formation of brain metastasis, EpCAM-directed CAR T-cell were injected into adjacent brain tissue, and animals received either anti-PD-1 or an isotype control.

RESULTS

Compared to controls receiving T-cell lacking a CAR, mice receiving EpCAM-directed CAR T-cell showed higher intratumoral CAR T-cell densities in the beginning after intraparenchymal injection. This finding was accompanied with reduced tumor growth and translated into a survival benefit. Additional anti-PD-1 treatment, however, did not affect intratumoral CAR T-cell persistence nor tumor growth and thereby did not provide an additional therapeutic effect.

CONCLUSION

CAR T-cell therapy for brain malignancies appears promising. However, additional anti-PD-1 treatment did not enhance intratumoral CAR T-cell persistence or effector function, highlighting the need for novel strategies to improve CAR T-cell therapy in solid tumors.

Regulation of the Function and Expression of EpCAM

The epithelial cell adhesion molecule (EpCAM) is a single transmembrane protein on the cell surface. Given its strong expression on epithelial cells and epithelial cell-derived tumors, EpCAM has been identified as a biomarker for circulating tumor cells (CTCs) and exosomes and a target for cancer therapy. As a cell adhesion molecule, EpCAM has a crystal structure that indicates that it forms a cis-dimer first and then probably a trans-tetramer to mediate intercellular adhesion. Through regulated intramembrane proteolysis (RIP), EpCAM and its proteolytic fragments are also able to regulate multiple signaling pathways, Wnt signaling in particular. Although great progress has been made, increasingly more findings have revealed the context-specific expression and function patterns of EpCAM and their regulation processes, which necessitates further studies to determine the structure, function, and expression of EpCAM under both physiological and pathological conditions, broadening its application in basic and translational cancer research.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

Enhancing the safety of CAR-T cell therapy: Synthetic genetic switch for spatiotemporal control

Chimeric antigen receptor T (CAR-T) cell therapy is a promising and precise targeted therapy for cancer that has demonstrated notable potential in clinical applications. However, severe adverse effects limit the clinical application of this therapy and are mainly caused by uncontrollable activation of CAR-T cells, including excessive immune response activation due to unregulated CAR-T cell action time, as well as toxicity resulting from improper spatial localization. Therefore, to enhance controllability and safety, a control module for CAR-T cells is proposed. Synthetic biology based on genetic engineering techniques is being used to construct artificial cells or organisms for specific purposes. This approach has been explored in recent years as a means of achieving controllability in CAR-T cell therapy. In this review, we summarize the recent advances in synthetic biology methods used to address the major adverse effects of CAR-T cell therapy in both the temporal and spatial dimensions.