MUC1-C Induces PD-L1 and Immune Evasion in Triple-Negative Breast Cancer

Exploring Myc puzzle: Insights into cancer, stem cell biology, and PPI networks

"The grand orchestrator," "Universal Amplifier," "double-edged sword," and "Undruggable" are just some of the Myc oncogene so-called names. It has been around 40 years since the discovery of the Myc, and it remains in the mainstream of cancer treatment drugs. Myc is part of basic helix-loop-helix leucine zipper (bHLH-LZ) superfamily proteins, and its dysregulation can be seen in many malignant human tumors. It dysregulates critical pathways in cells that are connected to each other, such as proliferation, growth, cell cycle, and cell adhesion, impacts miRNAs action, intercellular metabolism, DNA replication, differentiation, microenvironment regulation, angiogenesis, and metastasis. Myc, surprisingly, is used in stem cell research too. Its family includes three members, MYC, MYCN, and MYCL, and each dysfunction was observed in different cancer types. This review aims to introduce Myc and its function in the body. Besides, Myc deregulatory mechanisms in cancer cells, their intricate aspects will be discussed. We will look at promising drugs and Myc-based therapies. Finally, Myc and its role in stemness, Myc pathways based on PPI network analysis, and future insights will be explained.

The molecular crosstalk of the hippo cascade in breast cancer: A potential central susceptibility

The incidence of breast cancer is perpetually growing globally, and it remains a major public health problem and the leading cause of mortality in women. Though the aberrant activities of the Hippo pathway have been reported to be associated with cancer, constructive knowledge of the pathway connecting the various elements of breast cancer remains to be elucidated. The Hippo transducers, yes-associated protein (YAP) and transcriptional co-activator with PDZ binding motif (TAZ), are reported to be either tumor suppressors, oncogenes, or independent prognostic markers in breast cancer. Thus, there is further need for an explicative evaluation of the dilemma with this molecular contribution of Hippo transducers in modulating breast malignancy. In this review, we summarize the intricate crosstalk of the Hippo pathway in different aspects of breast malignancy, including stem-likeness, cellular signaling, metabolic adaptations, tumor microenvironment, and immune responses. The collective data shows that Hippo transducers play an indispensable role in mammary tumor formation, progression, and dissemination. However, the cellular functions of YAP/TAZ in tumorigenesis might be largely dependent on the mechanical and biophysical cues they interact with, as well as on the cell phenotype. This review provides a glimpse into the plausible biological contributions of the cascade to the inward progression of breast carcinoma and suggests potential therapeutic prospects.

Neoantigens and cancer-testis antigens as promising vaccine candidates for triple-negative breast cancer: Delivery strategies and clinical trials

Immunotherapy is gaining prominence as a promising strategy for treating triple-negative breast cancer (TNBC). Neoantigens (neoAgs) and cancer-testis antigens (CTAs) are tumor-specific targets originating from somatic mutations and epigenetic changes in cancer cells. These antigens hold great promise for personalized cancer vaccines, as supported by preclinical and early clinical evidence in TNBC. This review delves into the potential of neoAgs and CTAs as vaccine candidates, emphasizing diverse strategies and delivery approaches. It also highlights the current status of vaccination modalities undergoing clinical trials in TNBC therapy. A comprehensive understanding of neoAgs, CTAs, vaccination strategies, and innovative delivery methods is crucial for optimizing neoAg-based immunotherapies in clinical practice.

Cross-Talks between Raf Kinase Inhibitor Protein and Programmed Cell Death Ligand 1 Expressions in Cancer: Role in Immune Evasion and Therapeutic Implications

Innovations in cancer immunotherapy have resulted in the development of several novel immunotherapeutic strategies that can disrupt immunosuppression. One key advancement lies in immune checkpoint inhibitors (ICIs), which have shown significant clinical efficacy and increased survival rates in patients with various therapy-resistant cancers. This immune intervention consists of monoclonal antibodies directed against inhibitory receptors (e.g., PD-1) on cytotoxic CD8 T cells or against corresponding ligands (e.g., PD-L1/PD-L2) overexpressed on cancer cells and other cells in the tumor microenvironment (TME). However, not all cancer cells respond-there are still poor clinical responses, immune-related adverse effects, adaptive resistance, and vulnerability to ICIs in a subset of patients with cancer. This challenge showcases the heterogeneity of cancer, emphasizing the existence of additional immunoregulatory mechanisms in many patients. Therefore, it is essential to investigate PD-L1's interaction with other oncogenic genes and pathways to further advance targeted therapies and address resistance mechanisms. Accordingly, our aim was to investigate the mechanisms governing PD-L1 expression in tumor cells, given its correlation with immune evasion, to uncover novel mechanisms for decreasing PD-L1 expression and restoring anti-tumor immune responses. Numerous studies have demonstrated that the upregulation of Raf Kinase Inhibitor Protein (RKIP) in many cancers contributes to the suppression of key hyperactive pathways observed in malignant cells, alongside its broadening involvement in immune responses and the modulation of the TME. We, therefore, hypothesized that the role of PD-L1 in cancer immune surveillance may be inversely correlated with the low expression level of the tumor suppressor Raf Kinase Inhibitor Protein (RKIP) expression in cancer cells. This hypothesis was investigated and we found several signaling cross-talk pathways between the regulations of both RKIP and PD-L1 expressions. These pathways and regulatory factors include the MAPK and JAK/STAT pathways, GSK3β, cytokines IFN-γ and IL-1β, Sox2, and transcription factors YY1 and NFκB. The pathways that upregulated PD-L1 were inhibitory for RKIP expression and vice versa. Bioinformatic analyses in various human cancers demonstrated the inverse relationship between PD-L1 and RKIP expressions and their prognostic roles. Therefore, we suspect that the direct upregulation of RKIP and/or the use of targeted RKIP inducers in combination with ICIs could result in a more targeted anti-tumor immune response-addressing the therapeutic challenges related to PD-1/PD-L1 monotherapy alone.

circATAD2 mitigates CD8+ T cells antitumor immune surveillance in breast cancer via IGF2BP3/m6A/PD-L1 manner

Immune surveillance and chemotherapy sensitivity play critical functions in the tumorigenesis of breast cancer (BC). Emerging findings have indicated that circular RNA (circRNA) and N6-methyladenosine (m6A) both participate in the BC tumorigenesis. Here, present study aimed to investigate the roles of m6A-modified circATAD2 on BC and explore better understanding for BC precision therapeutic. Results reported that m6A-modifid circRNA (m6A-circRNA) microarray revealed the m6A-circRNA landscape in BC. M6A-modifid circATAD2 upregulated in BC samples and was closely correlated to poor prognosis. Functionally, circATAD2 promoted the immune evasion of BC cells and reduced the CD8+ T cells' killing effect. Mechanistically, MeRIP-seq unveiled the m6A modification in the 3'-UTR of PD-L1 mRNA, which was bound by circATAD2 and recognized by m6A reader IGF2BP3 to enhance PD-L1 mRNA stability and expression. In summary, these findings revealed the circATAD2/m6A/IGF2BP3/PD-L1 axis in BC immune surveillance, suggesting the potential that circATAD2 as a potential target for PD-L1-mediated BC.

MUC1 promotes cervical squamous cell carcinoma through ERK phosphorylation-mediated regulation of ITGA2/ITGA3

In contrast to the decreasing trends in developed countries, the incidence and mortality rates of cervical squamous cell carcinoma in China have increased significantly. The screening and identification of reliable biomarkers and candidate drug targets for cervical squamous cell carcinoma are urgently needed to improve the survival rate and quality of life of patients. In this study, we demonstrated that the expression of MUC1 was greater in neoplastic tissues than in non-neoplastic tissues of the cervix, and cervical squamous cell carcinoma patients with high MUC1 expression had significantly worse overall survival than did those with low MUC1 expression, indicating its potential for early diagnosis of cervical squamous cell carcinoma. Next, we explored the regulatory mechanism of MUC1 in cervical squamous cell carcinoma. MUC1 could upregulate ITGA2 and ITGA3 expression via ERK phosphorylation, promoting the proliferation and metastasis of cervical cancer cells. Further knockdown of ITGA2 and ITGA3 significantly inhibited the tumorigenesis of cervical cancer cells. Moreover, we designed a combination drug regimen comprising MUC1-siRNA and a novel ERK inhibitor in vivo and found that the combination of these drugs achieved better results in animals with xenografts than did MUC1 alone. Overall, we discovered a novel regulatory pathway, MUC1/ERK/ITGA2/3, in cervical squamous cell carcinoma that may serve as a potential biomarker and therapeutic target in the future.

Porphyromonas gingivalis suppresses oral squamous cell carcinoma progression by inhibiting MUC1 expression and remodeling the tumor microenvironment

Bacteria are the causative agents of various infectious diseases; however, the anti-tumor effect of some bacterial species has attracted the attention of many scientists. The human oral cavity is inhabited by abundant and diverse bacterial communities and some of these bacterial communities could play a role in tumor suppression. Therefore, it is crucial to find oral bacterial species that show anti-tumor activity on oral cancers. In the present study, we found that a high abundance of Porphyromonas gingivalis, an anaerobic periodontal pathogen, in the tumor microenvironment (TME) was positively associated with the longer survival of patients with oral squamous cell carcinoma (OSCC). An in vitro assay confirmed that P. gingivalis accelerated the death of OSCC cells by inducing cell cycle arrest at the G2/M phase, thus exerting its anti-tumor effect. We also found that P. gingivalis significantly decreased tumor growth in a 4-nitroquinoline-1-oxide-induced in situ OSCC mouse model. The transcriptomics data demonstrated that P. gingivalis suppressed the biosynthesis of mucin O-glycan and other O-glycans, as well as the expression of chemokines. Validation experiments further confirmed the downregulation of mucin-1 (MUC1) and C-X-C motif chemokine 17 (CXCL17) expression by P. gingivalis treatment. Flow cytometry analysis showed that P. gingivalis successfully reversed the immunosuppressive TME, thereby suppressing OSCC growth. In summary, the findings of the present study indicated that the rational use of P. gingivalis could serve as a promising therapeutic strategy for OSCC.

CAR-based immunotherapy for breast cancer: peculiarities, ongoing investigations, and future strategies

Surgery, chemotherapy, and endocrine therapy have improved the overall survival and postoperative recurrence rates of Luminal A, Luminal B, and HER2-positive breast cancers but treatment modalities for triple-negative breast cancer (TNBC) with poor prognosis remain limited. The effective application of the rapidly developing chimeric antigen receptor (CAR)-T cell therapy in hematological tumors provides new ideas for the treatment of breast cancer. Choosing suitable and specific targets is crucial for applying CAR-T therapy for breast cancer treatment. In this paper, we summarize CAR-T therapy's effective targets and potential targets in different subtypes based on the existing research progress, especially for TNBC. CAR-based immunotherapy has resulted in advancements in the treatment of breast cancer. CAR-macrophages, CAR-NK cells, and CAR-mesenchymal stem cells (MSCs) may be more effective and safer for treating solid tumors, such as breast cancer. However, the tumor microenvironment (TME) of breast tumors and the side effects of CAR-T therapy pose challenges to CAR-based immunotherapy. CAR-T cells and CAR-NK cells-derived exosomes are advantageous in tumor therapy. Exosomes carrying CAR for breast cancer immunotherapy are of immense research value and may provide a treatment modality with good treatment effects. In this review, we provide an overview of the development and challenges of CAR-based immunotherapy in treating different subtypes of breast cancer and discuss the progress of CAR-expressing exosomes for breast cancer treatment. We elaborate on the development of CAR-T cells in TNBC therapy and the prospects of using CAR-macrophages, CAR-NK cells, and CAR-MSCs for treating breast cancer.

Epithelial-to-mesenchymal transition in cancer progression: unraveling the immunosuppressive module driving therapy resistance

Cancer cells undergo phenotypic switching (cancer cell plasticity) in response to microenvironmental cues, including exposure to therapy/treatment. Phenotypic plasticity enables the cancer cells to acquire more mesenchymal traits promoting cancer cells' growth, survival, therapy resistance, and disease recurrence. A significant program in cancer cell plasticity is epithelial-to-mesenchymal transition (EMT), wherein a comprehensive reprogramming of gene expression occurs to facilitate the translational shift from epithelial-to-mesenchymal phenotypes resulting in increased invasiveness and metastasis. In addition, EMT plays a pivotal role in facilitating cancer cells' escape from the body's immune system using several mechanisms, such as the downregulation of major histocompatibility complex-mediated antigen presentation, upregulation of immune checkpoint molecules, and recruitment of immune-suppressive cells. Cancer cells' ability to undergo phenotypic switching and EMT-driven immune escape presents a formidable obstacle in cancer management, highlighting the need to unravel the intricate mechanisms underlying these processes and develop novel therapeutic strategies. This article discusses the role of EMT in promoting immune evasion and therapy resistance. We also discuss the ongoing research on developing therapeutic approaches targeting intrinsic and induced cell plasticity within the immune suppressive microenvironment. We believe this review article will update the current research status and equip researchers, clinicians, and other healthcare professionals with valuable insights enhancing their existing knowledge and shedding light on promising directions for future cancer research. This will facilitate the development of innovative strategies for managing therapy-resistant cancers and improving patient outcomes.

The Prognostic Value of CD39 as a Marker of Tumor-Specific T Cells in Triple-Negative Breast Cancer in Asian Women

Triple-negative breast cancer (TNBC) has a poor prognosis with limited therapeutic options available for affected patients. Efforts are ongoing to identify surrogate markers for tumor-specific CD8+ T cells that can predict the response to immune checkpoint inhibitor (ICI) therapies, such as programmed cell death protein 1 or programmed cell death ligand-1 blockade. We have previously identified tumor-specific CD39+CD8+ T cells in non-small cell lung cancer that might help predict patient responses to programmed cell death protein 1 or programmed cell death ligand-1 blockade. Based on this finding, we conducted a comparative interrogation of TNBC in an Asian cohort to evaluate the potential of CD39 as a surrogate marker of tumor-specific CD8+ T cells. Using ICI-treated TNBC mouse models (n = 24), flow cytometric analyses of peripheral blood mononuclear cells and tumor-infiltrating lymphocytes revealed that >99% of tumor-specific CD8+ T cells also expressed CD39. To investigate the relationship between CD39+CD8+ T-cell density and CD39 expression with disease prognosis, we performed multiplex immunohistochemistry staining on treatment-naive human TNBC tissues (n = 315). We saw that the proportion of CD39+CD8+ T cells in human TNBC tumors correlated with improved overall survival, as did the densities of other CD39+ immune cell infiltrates, such as CD39+CD68+ macrophages. Finally, increased CD39 expression on CD8+ T cells was also found to predict the response to ICI therapy (pembrolizumab) in a separate cohort of 11 TNBC patients. These findings support the potential of CD39+CD8+ T-cell density as a prognostic factor in Asian TNBC patients.

Targeting the NF-κB pathway as a potential regulator of immune checkpoints in cancer immunotherapy

Advances in cancer immunotherapy over the last decade have led to the development of several agents that affect immune checkpoints. Inhibitory receptors expressed on T cells that negatively regulate the immune response include cytotoxic T‑lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD1), which have been studied more than similar receptors. Inhibition of these proteins and other immune checkpoints can stimulate the immune system to attack cancer cells, and prevent the tumor from escaping the immune response. However, the administration of anti-PD1 and anti-CTLA4 antibodies has been associated with adverse inflammatory responses similar to autoimmune diseases. The current review discussed the role of the NF-κB pathway as a tumor promoter, and how it can govern inflammatory responses and affect various immune checkpoints. More precise knowledge about the communication between immune checkpoints and NF-κB pathways could increase the effectiveness of immunotherapy and reduce the adverse effects of checkpoint inhibitor therapy.

Rhodomyrtus tomentosa as a new anticancer molecular strategy in breast histology via Her2, IL33, EGFR, and MUC1

The prevalence of breast cancer among patients in Indonesia is significant. Indonesian individuals maintain the belief that cancer cannot be cured alone by pharmaceuticals and treatment; herbal remedies must be used in conjunction. Rhodomyrtus tomentosa, also known as Haramonting, is an indigenous Indonesian medicinal plant renowned for its copious antioxidant properties. The objective of study was to assess the impact of haramonting on breast cancer by examining the expression of various biomarker proteins associated with breast cancer. Haramonting was administered to breast cancer model mice at different doses over a period of 30 days. Subsequently, blood and breast samples were obtained for immunohistochemistry and enzyme-linked immunosorbent assays (ELISA). Authors have discovered that there has been a notable rise in the proliferation of epithelial cells in the duct lobes, resulting in the formation of ducts and lobules. Additionally, the researchers discovered that the breasts exhibited distinct clinical and histological alterations. Haramonting possesses the capacity to restore the concentrations of malondialdehyde (MDA) and superoxide dismutase (SOD) to normal levels in the blood serum of rats afflicted with cancer. The histopathological analysis of the breast tissue revealed elevated levels of Her2, IL33, EGFR, and MUC1. The authors also discovered a notable increase in the growth of epithelial cells, with two or more layers of cells reaching towards the centre of the duct. The size of the epithelial cells exhibits variability; however, this state ameliorates with the administration of a dosage of 300 mg/kgBW of this botanical specimen. This study proposes that Haramonting may be effective in treating breast cancer.

MUC1 and MUC16: critical for immune modulation in cancer therapeutics

The Mucin (MUC) family, a range of highly glycosylated macromolecules, is ubiquitously expressed in mammalian epithelial cells. Such molecules are pivotal in establishing protective mucosal barriers, serving as defenses against pathogenic assaults. Intriguingly, the aberrant expression of specific MUC proteins, notably Mucin 1 (MUC1) and Mucin 16 (MUC16), within tumor cells, is intimately associated with oncogenesis, proliferation, and metastasis. This association involves various mechanisms, including cellular proliferation, viability, apoptosis resistance, chemotherapeutic resilience, metabolic shifts, and immune surveillance evasion. Due to their distinctive biological roles and structural features in oncology, MUC proteins have attracted considerable attention as prospective targets and biomarkers in cancer therapy. The current review offers an exhaustive exploration of the roles of MUC1 and MUC16 in the context of cancer biomarkers, elucidating their critical contributions to the mechanisms of cellular signal transduction, regulation of immune responses, and the modulation of the tumor microenvironment. Additionally, the article evaluates the latest advances in therapeutic strategies targeting these mucins, focusing on innovations in immunotherapies and targeted drugs, aiming to enhance customization and accuracy in cancer treatments.

IRGM is a novel regulator of PD-L1 via promoting S6K1-mediated phosphorylation of YBX1 in hepatocellular carcinoma

Immunity-related GTPase M (IRGM), an Interferon-inducible protein, functions as a pivotal immunoregulator in multiple autoimmune diseases and infection. However, the role of IRGM in hepatocellular carcinoma (HCC) development remains unveiled. Here, we found interferon-γ (IFN-γ) treatment in HCC drastically triggered the expression of IRGM, and the high level of IRGM indicated poor prognosis in HCC patients. Functionally, IRGM promoted the malignant progression of HCC. Single-cell sequencing revealed that IRGM inhibition promoted the infiltration of CD8+ cytotoxic T lymphocytes (CTLs) with significant downregulation of PD-L1 expression in HCC. Furthermore, Immunoprecipitation-Mass Spectrometry assay revealed that IRGM interacted with transcription factor YBX1, which facilitated PD-L1 transcription. Mechanistically, IRGM promoted the interaction of YBX1 and phosphokinase S6K1, increasing phosphorylation and nuclear localization of YBX1, transcription of PD-L1. Additionally, the combination of IRGM inhibition with α-PD1 demonstrated a stronger anti-tumor effect compared to the single application of α-PD1. In summary, IRGM is a novel regulator of PD-L1, which suppresses CD8+ CTLs infiltration and function in HCC, resulting in cancer progression. This study may raise a novel therapeutic strategy combined with immune checkpoint inhibitors (ICIs) against HCC.

MUC1 Drives the Progression and Chemoresistance of Clear Cell Renal Carcinomas

While the transmembrane glycoprotein mucin 1 (MUC1) is clustered at the apical borders of normal epithelial cells, with transformation and loss of polarity, MUC1 is found at high levels in the cytosol and is uniformly distributed over the entire surface of carcinoma cells, where it can promote tumor progression and adversely affects the response to therapy. Clear cell renal cell carcinoma (ccRCC), the main histotype of kidney cancer, is typically highly resistant to conventional and targeted therapies for reasons that remain largely unknown. In this context, we investigated whether MUC1 also plays a pivotal role in the cellular and molecular events driving ccRCC progression and chemoresistance. We showed, using loss- and gain-of-function approaches in ccRCC-derived cell lines, that MUC1 not only influences tumor progression but also induces a multi-drug-resistant profile reminiscent of the activation of ABC drug efflux transporters. Overall, our results suggest that targeting MUC1 may represent a novel therapeutic approach to limit ccRCC progression and improve drug sensitivity.

Optimization of cancer immunotherapy on the basis of programmed death ligand-1 distribution and function

Programmed cell death protein-1 (PD-1)/programmed death ligand-1 (PD-L1) immune checkpoint blockade as a breakthrough in cancer immunotherapy has shown unprecedented positive outcomes in the clinic. However, the overall effectiveness of PD-L1 antibody is less than expected. An increasing number of studies have demonstrated that PD-L1 is widely distributed and expressed not only on the cell membrane but also on the inside of the cells as well as on the extracellular vesicles secreted by tumour cells. Both endogenous and exogenous PD-L1 play significant roles in influencing the therapeutic effect of anti-tumour immunity. Herein, we mainly focused on the distribution and function of PD-L1 and further summarized the potential targeted therapeutic strategies. More importantly, in addition to taking the overall expression abundance of PD-L1 as a predictive indicator for selecting corresponding PD-1/PD-L1 monoclonal antibodies (mAbs), we also proposed that personalized combination therapies based on the different distribution of PD-L1 are worth attention to achieve more efficient and effective therapeutic outcomes in cancer patients. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc.

Mucin1 as a potential molecule for cancer immunotherapy and targeted therapy

Mucin1 is a highly glycosylated type 1 transmembrane mucin that ranks second among 75 tumor-related antigens published by the National Cancer Institute, and has been identified as a possible therapeutic target over the past 30 years. MUC1 plays an important role in malignant transformation and disease evolution, including cell proliferation, survival, self-renewal, and metastatic invasion. MUC1 has been shown to interact with diverse effectors such as β-catenin, receptor tyrosine kinases, and cellular-abelsongene, which are of importance in the pathogenesis of various malignant tumors. Targeting MUC1 has been shown to be an effective way to induce tumor cell death in vivo and in vitro models. In recent years, a number of therapeutic strategies targeting MUC1 have been developed and their value for tumor therapy have been demonstrated experimentally. This review summarizes recent findings on the structure of MUC1, its expression in different tumors and its involved mechanism pathways, with emphasis on new progress in cancer therapy which related MUC1 in the past decade and evaluates their therapeutic effect.

Integrated Single-cell and Bulk RNA Sequencing Analysis Cross Talk between Ferroptosis-related Genes and Prognosis in Oral Cavity Squamous Cell Carcinoma

BACKGROUND

Ferroptosis is a new type of programmed apoptosis and plays an important role in tumour inhibition and immunotherapy.

OBJECTIVE

In this study, we aimed to explore the potential role of ferroptosis-related genes (FRGs) and the potential therapeutic targets in oral cavity squamous cell carcinoma (OCSCC).

METHODS

The transcription data of OCSCC samples were obtained from the Cancer Genome Atlas (TCGA) database as a training dataset. The prognostic FRGs were extracted by univariate Cox regression analysis. Then, we constructed a prognostic model using the least absolute shrinkage and selection operator (LASSO) and Cox analysis to determine the independent prognosis FRGs. Based on this model, risk scores were calculated for the OCSCC samples. The model's capability was further evaluated by the receiver operating characteristic curve (ROC). Then, we used the GSE41613 dataset as an external validation cohort to confirm the model's predictive capability. Next, the immune infiltration and somatic mutation analysis were applied. Lastly, single-cell transcriptomic analysis was used to identify the key cells.

RESULTS

A total of 12 prognostic FRGs were identified. Eventually, 6 FRGs were screened as independent predictors and a prognostic model was constructed in the training dataset, which significantly stratified OCSCC samples into high-risk and low-risk groups based on overall survival. The external validation of the model using the GSE41613 dataset demonstrated a satisfactory predictive capability for the prognosis of OCSCC. Further analysis revealed that patients in the highrisk group had distinct immune infiltration and somatic mutation patterns from low-risk patients. Mast cell infiltrations were identified as prognostic immune cells and played a role in OCSCC partly through ferroptosis.

CONCLUSION

We successfully constructed a novel 6 FRGs model and identified a prognostic immune cell, which can serve to predict clinical prognoses for OCSCC. Ferroptosis may be a new direction for immunotherapy of OCSCC.

Ferroptosis induction via targeting metabolic alterations in triple-negative breast cancer

Triple-negative breast cancer (TNBC), the most aggressive form of breast cancer, presents severe threats to women's health. Therefore, it is critical to find novel treatment approaches. Ferroptosis, a newly identified form of programmed cell death, is marked by the buildup of lipid reactive oxygen species (ROS) and high iron concentrations. According to previous studies, ferroptosis sensitivity can be controlled by a number of metabolic events in cells, such as amino acid metabolism, iron metabolism, and lipid metabolism. Given that TNBC tumors are rich in iron and lipids, inducing ferroptosis in these tumors is a potential approach for TNBC treatment. Notably, the metabolic adaptability of cancer cells allows them to coordinate an attack on one or more metabolic pathways to initiate ferroptosis, offering a novel perspective to improve the high drug resistance and clinical therapy of TNBC. However, a clear picture of ferroptosis in TNBC still needs to be completely revealed. In this review, we provide an overview of recent advancements regarding the connection between ferroptosis and amino acid, iron, and lipid metabolism in TNBC. We also discuss the probable significance of ferroptosis as an innovative target for chemotherapy, radiotherapy, immunotherapy, nanotherapy and natural product therapy in TNBC, highlighting its therapeutic potential and application prospects.

Identifying a locus in super-enhancer and its resident NFE2L1/MAFG as transcriptional factors that drive PD-L1 expression and immune evasion

Although the transcriptional regulation of the programmed death ligand 1 (PD-L1) promoter has been extensively studied, the transcription factor residing in the PD-L1 super-enhancer has not been comprehensively explored. Through saturated CRISPR-Cas9 screening of the core region of the PD-L1 super-enhancer, we have identified a crucial genetic locus, referred to as locus 22, which is essential for PD-L1 expression. Locus 22 is a potential binding site for NFE2:MAF transcription factors. Although genetic silencing of NRF2 (NFE2L2) did not result in a reduction of PD-L1 expression, further analysis reveals that MAFG and NFE2L1 (NRF1) play a critical role in the expression of PD-L1. Importantly, lipopolysaccharides (LPS) as the major component of intratumoral bacteria could greatly induce PD-L1 expression, which is dependent on the PD-L1 super-enhancer, locus 22, and NFE2L1/MAFG. Mechanistically, genetic modification of locus 22 and silencing of MAFG greatly reduce BRD4 binding and loop formation but have minimal effects on H3K27Ac modification. Unlike control cells, cells with genetic modification of locus 22 and silencing of NFE2L1/MAFG failed to escape T cell-mediated killing. In breast cancer, the expression of MAFG is positively correlated with the expression of PD-L1. Taken together, our findings demonstrate the critical role of locus 22 and its associated transcription factor NFE2L1/MAFG in super-enhancer- and LPS-induced PD-L1 expression. Our findings provide new insight into understanding the regulation of PD-L1 transcription and intratumoral bacteria-mediated immune evasion.

Application of Biosensors in Detecting Breast Cancer Metastasis

Breast cancer has garnered global attention due to its high incidence worldwide, and even more noteworthy is that approximately 90% deaths due to breast cancer are attributed to cancer metastasis. Therefore, the early diagnosis of breast cancer metastasis holds significant importance for reducing mortality outcomes. Biosensors play a crucial role in the early detection of metastatic breast cancer due to their advantages, such as ease of use, portability, and real-time analysis capabilities. This review primarily described various types of sensors for detecting breast cancer metastasis based on biomarkers and cell characteristics, including electrochemical, optical, and microfluidic chips. We offered detailed descriptions of the performance of these various biosensors and made comparisons between them. Furthermore, we described the pathology of breast cancer and summarized commonly used biomarkers for metastatic breast cancer. Finally, we discussed the advantages of current-stage biosensors and the challenges that need to be addressed, as well as prospects for their future development.

The Therapeutic Effects of MUC1-C shRNA@Fe3O4 Magnetic Nanoparticles in Alternating Magnetic Fields on Triple-Negative Breast Cancer

Purpose

Improving the treatment of triple-negative breast cancer (TNBC) is a serious challenge today. The primary objective of this study was to construct MUC1-C shRNA@ Fe3O4 magnetic nanoparticles (MNPs) and investigate their potential therapeutic benefits in alternating magnetic fields (AMF) on TNBC.

Methods

Firstly, we verified the high expression of MUC1 in TNBC and synthesized specific MUC1-C shRNA plasmids (MUC1-C shRNA). Then, we prepared and characterized MUC1-C shRNA@Fe3O4 MNPs and confirmed their MUC1-C gene silencing effect and magneto-thermal conversion ability in AMF. Moreover, the inhibitory effects on TNBC in vitro and in vivo were observed as well as biosafety. Finally, the protein levels of BCL-2-associated X protein (Bax), cleaved-caspase3, glutathione peroxidase inhibitor 4 (GPX4), nuclear factor erythroid 2-related factor 2 (NRF2), and ferritin heavy chain 1 (FTH1) in TNBC cells and tissues were examined, and it was speculated that apoptosis and ferroptosis were involved in the synergistic treatment.

Results

MUC1-C shRNA@ Fe3O4 MNPs have a size of ~75 nm, with an encapsulation rate of (29.78±0.63) %, showing excellent gene therapy and magnetic hyperthermia functions. Under a constant AMF (3Kw) and a set concentration (200µg mL-1), the nanoparticles could be rapidly warmed up within 20 minutes and stabilized at about 43 °C. It could be uptaken by TNBC cells through endocytosis and significantly inhibit their proliferation and migration, with a growth inhibition rate of 79.22% for TNBC tumors. After treatment, GPX4, NRF2, and FTH1 expression levels in TNBC cells and tumor tissues were suppressed, while Bax and cleaved-caspase3 were increased. As key therapeutic measures, gene therapy, and magnetic hyperthermia have shown a synergistic effect in this treatment strategy, with a combined index (q index) of 1.23.

Conclusion

In conclusion, we developed MUC1-C shRNA@Fe3O4 MNPs with magnetic hyperthermia and gene therapy functions, which have shown satisfactory therapeutic effects on TNBC without significant side effects. This study provides a potential option for the precision treatment of TNBC.

Mucin 1 promotes salivary gland cancer cell proliferation and metastasis by regulating the epidermal growth factor receptor signaling pathway

Background/purpose

Salivary gland cancer (SGC) is the common malignant tumor of the head and neck region with poor prognosis. Mucin 1 (MUC1) has been reported to be associated with the development of cancer. However, whether MUC1 contributed to the progression of SGC remains to be explored.

Materials and methods

Immunohistochemical analysis was used to explore the expression levels of MUC1 in SGC tissues. Cell proliferation, colony formation, wound healing, transwell, and xenograft assays were performed to examine the effects of MUC1 on SGC in vitro and in vivo.

Results

We found that the expression level of MUC1 was significantly upregulated in SGC tissues, and the expression level of MUC1 was significantly correlated with lymph node metastasis and TNM stage of SGC. Further exploration demonstrated that MUC1 knockdown drastically inhibited, while its overexpression promoted, cell growth, colony formation, migration, and invasion abilities of SGC cells in vitro. MUC1 knockdown significantly inhibited tumor growth in vivo, and vice versa. More importantly, we found that MUC1 promotes malignant phenotypes of SGC cells by regulating the epidermal growth factor receptor (EGFR) signaling pathway.

Conclusion

Our results revealed that MUC1 promotes the development of SGC by mediating the EGFR signaling pathway, which highlights the potential therapeutic target of MUC1/ EGFR in SGC.

Remodeled tumor immune microenvironment (TIME) parade via natural killer cells reprogramming in breast cancer

Breast cancer (BC) is the main cause of cancer-related mortality among women globally. Despite substantial advances in the identification and management of primary tumors, traditional therapies including surgery, chemotherapy, and radiation cannot completely eliminate the danger of relapse and metastatic illness. Metastasis is controlled by microenvironmental and systemic mechanisms, including immunosurveillance. This led to the evolvement of immunotherapies that has gained much attention in the recent years for cancer treatment directed to the innate immune system. The long forgotten innate immune cells known as natural killer (NK) cells have emerged as novel targets for more effective therapeutics for BC. Normally, NK cells has the capacity to identify and eradicate tumor cells either directly or by releasing cytotoxic granules, chemokines and proinflammatory cytokines. Yet, NK cells are exposed to inhibitory signals by cancer cells, which causes them to become dysfunctional in the immunosuppressive tumor microenvironment (TME) in BC, supporting tumor escape and spread. Potential mechanisms of NK cell dysfunction in BC metastasis have been recently identified. Understanding these immunologic pathways driving BC metastasis will lead to improvements in the current immunotherapeutic strategies. In the current review, we highlight how BC evades immunosurveillance by rendering NK cells dysfunctional and we shed the light on novel NK cell- directed therapies.

The multifaceted role of MUC1 in tumor therapy resistance

Tumor therapeutic resistances are frequently linked to the recurrence and poor prognosis of cancers and have been a key bottleneck in clinical tumor treatment. Mucin1 (MUC1), a heterodimeric transmembrane glycoprotein, exhibits abnormally overexpression in a variety of human tumors and has been confirmed to be related to the formation of therapeutic resistance. In this review, the multifaceted roles of MUC1 in tumor therapy resistance are summarized from aspects of pan-cancer principles shared among therapies and individual mechanisms dependent on different therapies. Concretely, the common mechanisms of therapy resistance across cancers include interfering with gene expression, promoting genome instability, modifying tumor microenvironment, enhancing cancer heterogeneity and stemness, and activating evasion and metastasis. Moreover, the individual mechanisms of therapy resistance in chemotherapy, radiotherapy, and biotherapy are introduced. Last but not least, MUC1-involved therapy resistance in different types of cancers and MUC1-related clinical trials are summarized.

Single-cell transcriptome sequencing of B-cell heterogeneity and tertiary lymphoid structure predicts breast cancer prognosis and neoadjuvant therapy efficacy

BACKGROUND

Breast cancer (BC) is a highly heterogeneous disease, and although immunotherapy has recently increased patient survival in a number of solid and hematologic malignancies, most BC subtypes respond poorly to immune checkpoint blockade therapy (ICB). B cells, particularly those that congregate in tertiary lymphoid structures (TLS), play a significant role in antitumour immunity. However, B-cell heterogeneity at single-cell resolution and its clinical significance with TLS in BC need to be explored further.

METHODS

Primary tumour lesions and surrounding normal tissues were taken from 14 BC patients, totaling 124,587 cells, for single-cell transcriptome sequencing and bioinformatics analysis.

RESULTS

Based on the usual markers, the single-cell transcriptome profiles were classified into various clusters. A thorough single-cell study was conducted with a focus on tumour-infiltrating B cells (TIL-B) and tumour-associated neutrophils (TAN). TIL-B was divided into five clusters, and unusual cell types, such as follicular B cells, which are strongly related to immunotherapy efficacy, were identified. In BC, TAN and TIL-B infiltration are positively correlated, and at the same time, compared with TLS-high, TAN and TIL-B in TLS-low group are significantly positively correlated.

CONCLUSIONS

In conclusion, our study highlights the heterogeneity of B cells in BC, explains how B cells and TLS contribute significantly to antitumour immunity at both the single-cell and clinical level, and offers a straightforward marker for TLS called CD23. These results will offer more pertinent information on the applicability and effectiveness of tumour immunotherapy for BC.

Polarization of Cancer-Associated Macrophages Maneuver Neoplastic Attributes of Pancreatic Ductal Adenocarcinoma

Mounting evidence links the phenomenon of enhanced recruitment of tumor-associated macrophages towards cancer bulks to neoplastic growth, invasion, metastasis, immune escape, matrix remodeling, and therapeutic resistance. In the context of cancer progression, naïve macrophages are polarized into M1 or M2 subtypes according to their differentiation status, gene signatures, and functional roles. While the former render proinflammatory and anticancer effects, the latter subpopulation elicits an opposite impact on pancreatic ductal adenocarcinoma. M2 macrophages have gained increasing attention as they are largely responsible for molding an immune-suppressive landscape. Through positive feedback circuits involving a paracrine manner, M2 macrophages can be amplified by and synergized with neighboring neoplastic cells, fibroblasts, endothelial cells, and non-cell autonomous constituents in the microenvironmental niche to promote an advanced disease state. This review delineates the molecular cues expanding M2 populations that subsequently convey notorious clinical outcomes. Future therapeutic regimens shall comprise protocols attempting to abolish environmental niches favoring M2 polarization; weaken cancer growth typically assisted by M2; promote the recruitment of tumoricidal CD8⁺ T lymphocytes and dendritic cells; and boost susceptibility towards gemcitabine as well as other chemotherapeutic agents.

TIMELESS upregulates PD-L1 expression and exerts an immunosuppressive role in breast cancer

BACKGROUND

Upregulation of the PD-L1 (CD274) immune checkpoint ligand on the tumor surface facilitates tumor immune escape and limits the application of immunotherapy in various cancers, including breast cancer. However, the mechanisms underlying high PD-L1 levels in cancers are still poorly understood.

METHODS

Bioinformatics analyses and in vivo and in vitro experiments were carried out to assess the association between CD8⁺ T lymphocytes and TIMELESS (TIM) expression, and to discover the mechanisms of TIM, the transcription factor c-Myc, and PD-L1 in breast cancer cell lines.

RESULTS

The circadian gene TIM enhanced PD-L1 transcription and facilitated the aggressiveness and progression of breast cancer through the intrinsic and extrinsic roles of PD-L1 overexpression. Bioinformatic analyses of our RNA sequencing data in TIM-knockdown breast cancer cells and public transcriptomic datasets showed that TIM might play an immunosuppressive role in breast cancer. We found that TIM expression was inversely associated with CD8⁺ T lymphocyte infiltration in human breast cancer samples and subcutaneous tumor tissues. In vivo and in vitro experiments demonstrated that TIM knockdown increased CD8⁺ T lymphocyte antitumor activity. Furthermore, our results showed that TIM interacts with c-Myc to enhance the transcriptional capability of PD-L1 and facilitates the aggressiveness and progression of breast cancer through the intrinsic and extrinsic roles of PD-L1 overexpression. Moreover, public database analysis suggested that high TIM levels were positively related to PD-L1 inhibitor therapeutic response.

CONCLUSIONS

Mechanistically, we first found that TIM could upregulate PD-L1 by interacting with c-Myc to enhance the transcriptional capability of c-Myc to PD-L1. Altogether, our findings not only provide a novel therapeutic strategy to treat breast cancer by targeting the oncogenic effect of TIM but also indicate that TIM is a promising biomarker for predicting the benefit of anti-PD-L1 immunotherapy.

Preclinical and Basic Research Strategies for Overcoming Resistance to Targeted Therapies in HER2-Positive Breast Cancer

The amplification of epidermal growth factor receptor 2 (HER2) is associated with a poor prognosis and HER2 gene is overexpressed in approximately 15-30% of breast cancers. In HER2-positive breast cancer patients, HER2-targeted therapies improved clinical outcomes and survival rates. However, drug resistance to anti-HER2 drugs is almost unavoidable, leaving some patients with an unmet need for better prognoses. Therefore, exploring strategies to delay or revert drug resistance is urgent. In recent years, new targets and regimens have emerged continuously. This review discusses the fundamental mechanisms of drug resistance in the targeted therapies of HER2-positive breast cancer and summarizes recent research progress in this field, including preclinical and basic research studies.

Surface engineering of hollow gold nanoparticle with mesenchymal stem cell membrane and MUC-1 aptamer for targeted theranostic application against metastatic breast cancer

Mesenchymal stem cell membrane (MSCM)-coated biomimetic doxorubicin-loaded hollow gold nanoparticles were fabricated and decorated with MUC1 aptamer in order to provide smart theranostic platform. The prepared targeted nanoscale biomimetic platform was extensively characterized and evaluated in terms of selective delivery of DOX and CT-scan imaging. The fabricated system illustrated spherical morphology with 118 nm in diameter. Doxorubicin was loaded into the hollow gold nanoparticles through physical absorption technique with encapsulation efficiency and loading content of 77%±10 and 31%±4, respectively. The in vitro release profile demonstrated that the designed platform could respond to acidic environment, pH 5.5 and release 50% of the encapsulated doxorubicin during 48 h, while 14% of the encapsulated doxorubicin was released in physiological condition, pH 7.4 up to 48 h. The in vitro cytotoxicity experiments on 4T1 as MUC1 positive cell line illustrated that the targeted formulation could significantly increase mortality at 0.468 and 0.23 µg/ml of equivalent DOX concentration compared to non-targeted formulation while this cytotoxicity was not observed in CHO as MUC1 negative cell line. Furthermore, in vivo experiments showed high tumor accumulation of the targeted formulation even 24 h after intravenous injection which induced effective tumor growth suppression against 4T1 tumor bearing mice. On the other hand, existence of hollow gold in this platform provided CT scan imaging capability of the tumor tissue in 4T1 tumor bearing mice up to 24 h post-administration. The obtained results indicated that the designed paradigm are promising and safe theranostic system for fighting against metastatic breast cancer.

The NF-ĸB p50 subunit generated by KPC1-mediated ubiquitination and limited proteasomal processing, suppresses tumor growth

Nuclear factor-ĸB (NF-ĸB) is an important transcriptional regulator of key cellular processes, including cell cycle, immune response, and malignant transformation. We found that the ubiquitin ligase Kip1 ubiquitination-promoting complex subunit 1 (KPC1; also known as Ring finger protein 123 - RNF123) stimulates ubiquitination and limited proteasomal processing of the p105 NF-ĸB precursor to generate p50, the active subunit of the heterodimeric transcription factor. KPC1 binds to the ankyrin repeats' (AR) domain of NF-ĸB p105 via a short binding site of 7 amino acids-968-WILVRLW-974. Though mature NF-ĸB is overexpressed and constitutively active in different tumors, we found that overexpression of the p50 subunit, exerts a strong tumor suppressive effect. Furthermore, excess of KPC1 that stimulates generation of p50 from the p105 precursor, also results in a similar effect. Analysis of transcripts of glioblastoma and breast tumors revealed that excess of p50 stimulates expression of many NF-ĸB-regulated tumor suppressive genes. Using human xenograft tumor models in different immune compromised mice, we demonstrated that the immune system plays a significant role in the tumor suppressive activity of p50:p50 homodimer stimulating the expression of the pro-inflammatory cytokines CCL3, CCL4, and CCL5 in both cultured cells and in the xenografts. Expression of these cytokines leads to recruitment of macrophages and NK cells, which restrict tumor growth. Finally, p50 inhibits the expression of the programmed cell death-ligand 1 (PDL1), establishing an additional level of a strong tumor suppressive response mediated by the immune system.

Antitumor effect of a novel humanized MUC1 antibody-drug conjugate on triple-negative breast cancer

Breast cancer is the most common malignant cancer in women. Triple-negative breast cancer (TNBC) has a poorer prognosis than other subtypes and is challenging to treat. MUC1 is a therapeutic target in breast and pancreatic cancer. We developed a novel humanized antibody that specifically binds MUC1 expressed in breast cancer cells and conjugated a humanized MUC1 (HzMUC1) antibody to monomethyl auristatin (MMAE). HzMUC1-MMAE showed an anti-proliferative effect on HER2 positive trastuzumab-resistant breast cancer. Immunoprecipitation indicated that HzMUC1 recognized native MUC1 in TNBC cells. Confocal microscopy showed that HzMUC1 bound MUC1 on the surface of TNBC cells, and the conjugates exhibited the same binding ability to HCC70 as unconjugated HzMUC1 by cell-based ELISA. Treatment of TNBC cells with HzMUC1-MMAE reduced growth of MUC1-positive cells and induced G2/M cell cycle arrest and apoptosis. In a mouse model of breast cancer, HzMUC1-MMAE significantly reduced the growth of tumors established by subcutaneous injection of HCC70 TNBC cells. Therefore, HzMUC1-ADC has therapeutic potential for TNBC.

Targeting KK-LC-1 inhibits malignant biological behaviors of triple-negative breast cancer

BACKGROUND

Cancer/testis antigens (CTAs) participate in the regulation of malignant biological behaviors in breast cancer. However, the function and mechanism of KK-LC-1, a member of the CTA family, in breast cancer are still unclear.

METHODS

Bioinformatic tools, immunohistochemistry, and western blotting were utilized to detect the expression of KK-LC-1 in breast cancer and to explore the prognostic effect of KK-LC-1 expression in breast cancer patients. Cell function assays, animal assays, and next-generation sequencing were utilized to explore the function and mechanism of KK-LC-1 in the malignant biological behaviors of triple-negative breast cancer. Small molecular compounds targeting KK-LC-1 were also screened and drug susceptibility testing was performed.

RESULTS

KK-LC-1 was significantly highly expressed in triple-negative breast cancer tissues than in normal breast tissues. KK-LC-1 high expression was related to poor survival outcomes in patients with breast cancer. In vitro studies suggested that KK-LC-1 silencing can inhibit triple-negative breast cancer cell proliferation, invasion, migration, and scratch healing ability, increase cell apoptosis ratio, and arrest the cell cycle in the G0-G1 phase. In vivo studies have suggested that KK-LC-1 silencing decreases tumor weight and volume in nude mice. Results showed that KK-CL-1 can regulate the malignant biological behaviors of triple-negative breast cancer via the MAL2/MUC1-C/PI3K/AKT/mTOR pathway. The small-molecule compound Z839878730 had excellent KK-LC-1 targeting ability and cancer cell killing ability. The EC₅₀ value was 9.7 μM for MDA-MB-231 cells and 13.67 µM for MDA-MB-468 cells. Besides, Z839878730 has little tumor-killing effect on human normal mammary epithelial cells MCF10A and can inhibit the malignant biological behaviors of triple-negative breast cancer cells by MAL2/MUC1-C/PI3K/AKT/mTOR pathway.

CONCLUSIONS

Our findings suggest that KK-LC-1 may serve as a novel therapeutic target for triple-negative breast cancer. Z839878730, which targets KK-LC-1, presents a new path for breast cancer clinical treatment.

Targeting ATAD3A-PINK1-mitophagy axis overcomes chemoimmunotherapy resistance by redirecting PD-L1 to mitochondria

Only a small proportion of patients with triple-negative breast cancer benefit from immune checkpoint inhibitor (ICI) targeting PD-1/PD-L1 signaling in combination with chemotherapy. Here, we discovered that therapeutic response to ICI plus paclitaxel was associated with subcellular redistribution of PD-L1. In our immunotherapy cohort of ICI in combination with nab-paclitaxel, tumor samples from responders showed significant distribution of PD-L1 at mitochondria, while non-responders showed increased accumulation of PD-L1 on tumor cell membrane instead of mitochondria. Our results also revealed that the distribution pattern of PD-L1 was regulated by an ATAD3A-PINK1 axis. Mechanistically, PINK1 recruited PD-L1 to mitochondria for degradation via a mitophagy pathway. Importantly, paclitaxel increased ATAD3A expression to disrupt proteostasis of PD-L1 by restraining PINK1-dependent mitophagy. Clinically, patients with tumors exhibiting high expression of ATAD3A detected before the treatment with ICI in combination with paclitaxel had markedly shorter progression-free survival compared with those with ATAD3A-low tumors. Preclinical results further demonstrated that targeting ATAD3A reset a favorable antitumor immune microenvironment and increased the efficacy of combination therapy of ICI plus paclitaxel. In summary, our results indicate that ATAD3A serves not only as a resistant factor for the combination therapy of ICI plus paclitaxel through preventing PD-L1 mitochondrial distribution, but also as a promising target for increasing the therapeutic responses to chemoimmunotherapy.

Cytotoxic Lymphocyte-Related Gene Signature in Triple-Negative Breast Cancer

To curate the signature genes of cytotoxic lymphocytes (CLs) and explore the heterogeneity based on the CL-related (CLR) gene signature, we analyzed the gene expression of 592 patients with histologically diagnosed triple-negative breast cancer. Based on the 13-gene panel, CLR signatures were curated and associated with the stage of tumor size. Patients in the CLR-low group exhibited the worse overall survival (OS) (median OS, 75.23 months vs. 292.66 months, p < 0.0001) and were characterized by the upregulation of the NF-κB, Wnt, and p53 pathways, the positive regulation of angiogenesis, and a higher expression of immune checkpoints including CTLA4, LAG3, CD86, ICOS, ICOSLG, and TNFSF9. In cancer immunotherapy cohorts (GSE157284, GSE35640, IMvigor210), a higher CLR signature score was remarkably associated with greater tumor shrinkage and immune characteristics consisting of higher PD-L1 and neoantigen expression, as well as an inflamed tumor microenvironment. In the pan-cancer atlas, the CLR signature was notably associated with patient survival and revealed a profound heterogeneity across the malignancy types. In sum, the CLR signature is a promising indicator for immune characteristics, tumor shrinkage, and survival outcomes following cancer immunotherapy in addition to the prognostic heterogeneity in the pan-cancer atlas.

MYC Overexpression Drives Immune Evasion in Hepatocellular Carcinoma That Is Reversible through Restoration of Proinflammatory Macrophages

Cancers evade immune surveillance, which can be reversed through immune-checkpoint therapy in a small subset of cases. Here, we report that the MYC oncogene suppresses innate immune surveillance and drives resistance to immunotherapy. In 33 different human cancers, MYC genomic amplification and overexpression increased immune-checkpoint expression, predicted nonresponsiveness to immune-checkpoint blockade, and was associated with both Th2-like immune profile and reduced CD8 T-cell infiltration. MYC transcriptionally suppressed innate immunity and MHCI-mediated antigen presentation, which in turn impeded T-cell response. Combined, but not individual, blockade of PDL1 and CTLA4 could reverse MYC-driven immune suppression by leading to the recruitment of proinflammatory antigen-presenting macrophages with increased CD40 and MHCII expression. Depletion of macrophages abrogated the antineoplastic effects of PDL1 and CTLA4 blockade in MYC-driven hepatocellular carcinoma (HCC). Hence, MYC is a predictor of immune-checkpoint responsiveness and a key driver of immune evasion through the suppression of proinflammatory macrophages. The immune evasion induced by MYC in HCC can be overcome by combined PDL1 and CTLA4 blockade.

SIGNIFICANCE

Macrophage-mediated immune evasion is a therapeutic vulnerability of MYC-driven cancers, which has implications for prioritizing MYC-driven hepatocellular carcinoma for combination immunotherapy.

Modular Peptide Probe for Protein Analysis

The analysis and regulation of proteins are of great significance for the development of disease diagnosis and treatment. However, complicated analytical environment and complex protein structure severely limit the accuracy of their analysis results. Nowadays, ascribing to the editability and bioactivity of peptides, peptide-based probes could meet the requirements of good selectivity and high affinity to overcome the challenges. In this review, we summarize the advances in the use of modular peptide probes for proteins analysis. It focuses on how to design and optimize the structure of probes, as well as their performance. Then, the strategies and application to improve the analysis result of modular peptide probes are introduced. Finally, we also discuss current challenge and provide some ideas for the future direction for modular peptide probes, hoping to accelerate their clinical transformation.

MUC1 promotes lung metastases of liver cancer by impairing anti-tumor immunity

PURPOSE

MUC1 is a membrane bound protein that can regulate tumor progression but its role in tumor metastasis and the metastatic microenvironment remains unclear.

METHODS

We performed differential gene analysis for primary liver cancer (n = 31) and lung metastases (n = 31) using the Gene Expression Omnibus (GEO) dataset (GSE141016) and obtained RNA sequencing data from 374 liver cancer and 50 normal tissues from The Cancer Genome Atlas (TCGA). We analyzed the prognostic value of MUC1 and the relationship between MUC1 and the TME using online databases and a clinical cohort. Immunohistochemistry detected MUC1 in normal liver, liver cancer, and lung metastases. Multiplex immunohistochemistry staining detected immune cells in the metastatic microenvironment.

RESULTS

High MUC1 expression levels in hepatocellular carcinoma are associated with worse clinical prognosis and higher rates of lung metastasis. In addition, we observed a correlation between MUC1 and multiple immune cells in the metastatic microenvironment. In paired primary liver cancer and lung metastatic tumor tissues from the same patient, we observed higher MUC1 protein levels in lung metastases than in primary liver cancer. Furthermore, MUC1 was negatively correlated with CD8+T and Treg cells in the metastatic tumor microenvironment and positively correlated with DC. In addition, we found that MUC1 was associated with CD8+T cell activation and function using flow cytometry in another cohort of patients with liver cancer.

CONCLUSION

These data confirm the potential of MUC1 as a prognostic marker and therapeutic target.

Cytotoxic activity of anti-mucin 1 chimeric antigen receptor T cells expressing PD-1-CD28 switch receptor against cholangiocarcinoma cells

BACKGROUND AIMS

Cholangiocarcinoma (CCA) is a lethal bile-duct cancer that is difficult to treat by current standard procedures. This drawback has prompted us to develop adoptive T-cell therapy for CCA, which requires an appropriate target antigen for binding of chimeric antigen receptor (CAR) T cells. Mucin 1 (MUC1), an overexpressed protein in CCA cells, is a potential target antigen for the CAR T-cell development. However, MUC1 overexpression also is associated with the upregulation of programmed death-ligand 1 (PD-L1), an immune checkpoint protein that prohibits anti-tumor functions of T cells, probably causing poor overall survival of patients with CCA.

METHODS

To overcome this problem, we developed anti-MUC1-CAR T cells containing PD-1-CD28 switch receptor (SR), namely αM.CAR/SR T cells, to target MUC1 and switch on the inhibitory signal of PD-1/PD-L1 interaction to activate CD28 signaling. Our lentiviral construct contains the sequences that encode anti-MUC1-single chain variable fragment, CD137 and CD3ζ, linked with P2A, PD-1 and CD28.

RESULTS

Initially, the upregulations of MUC1 and PD-L1 proteins were confirmed in CCA cell lines. αM.CAR and SR were co-expressed in 53.53 ± 13.89% of transduced T cells, mainly CD8⁺ T cells (85.7 ± 0.75%, P<0.0001) with the effector memory phenotype (59.22 ± 16.31%, P < 0.01). αM.CAR/SR T cells produced high levels of intracellular tumor necrosis factor-α and interferon-γ in response to the activation by CCA cells expressing MUC1, including KKU-055 (27.18 ± 4.38% and 27.33 ± 5.55%, respectively, P < 0.05) and KKU-213A (47.37 ± 12.67% and 54.55 ± 8.66%, respectively, P < 0.01). Remarkably, the cytotoxic function of αM.CAR/SR T cells against KKU-213A cells expressing PD-L1 was significantly enhanced compared with the αM.CAR T cells (70.69 ± 14.38% versus 47.15 ± 8.413%, respectively; P = 0.0301), correlated with increased granzyme B production (60.6 ± 9.89% versus 43.2 ± 8.95%, respectively; P = 0.0402). Moreover, the significantly enhanced disruption of KKU-213A spheroids by αM.CAR/SR T cells (P = 0.0027), compared with αM.CAR T cells, was also observed.

CONCLUSION

Taken together, the cytotoxic function of αM.CAR/SR T cells was enhanced over the αM.CAR T cells, which are potential to be further tested for CCA treatment.

The complex network of transcription factors, immune checkpoint inhibitors and stemness features in colorectal cancer: A recent update

Cancer immunity is regulated by several mechanisms that include co-stimulatory and/or co-inhibitory molecules known as immune checkpoints expressed by the immune cells. In colorectal cancer (CRC), CTLA-4, LAG3, TIM-3 and PD-1 are the major co-inhibitory checkpoints involved in tumor development and progression. On the other hand, the deregulation of transcription factors and cancer stem cells activity plays a major role in the development of drug resistance and in the spread of metastatic disease in CRC. In this review, we describe how the modulation of such transcription factors affects the response of CRC to therapies. We also focus on the role of cancer stem cells in tumor metastasis and chemoresistance and discuss both preclinical and clinical approaches for targeting stem cells to prevent their tumorigenic effect. Finally, we provide an update on the clinical applications of immune checkpoint inhibitors in CRC and discuss the regulatory effects of transcription factors on the expression of the immune inhibitory checkpoints with specific focus on the PD-1 and PD-L1 molecules.

Multi-Targeting Nano-Systems Targeting Heterogeneous Cancer Cells for Therapeutics and Biomarker Detection

Cancer heterogeneity plays a vital part in cancer resistance and metastasis. To provide a reliable approach to exert a therapy action and evaluate its efficiency in heterogeneous cancer cells, a multiple targeting delivery vector composed of histone encapsulating the therapeutic or diagnostic agent, hyaluronic acid targeting CD44 overexpressed in stem tumor cells, SYL3C aptamer targeting epithelial cell adhesion molecule (EpCAM) overexpressed in epithelial cancer cells, and CL4 aptamer targeting epidermal growth factor receptor (EGFR) overexpressed in mesenchymal cancer cells, is developed. The vector can efficiently target different cancer cells and circulating tumor cells (CTCs) in the peripheral blood of patients for mucin 1 (MUC1) knockout. Furthermore, the multiple targeting vector can be used to co-encapsulate three types of molecular beacons for probing various mRNA biomarkers at single-cell resolution after genome editing. This study provides an efficient approach for exerting therapeutic actions in heterogeneous cancer cells and assessing the therapeutic efficacy by detection of cancer biomarkers via liquid biopsy.

c-MYC mediates the crosstalk between breast cancer cells and tumor microenvironment

The MYC oncogenic family is dysregulated in diverse tumors which is generally linked to the poor prognosis of tumors. The members in MYC family are transcription factors which are responsible for the regulation of various genes expression. Among them, c-MYC is closely related to the progression of tumors. Furthermore, c-MYC aberrations is tightly associated with the prevalence of breast cancer. Tumor microenvironment (TME) is composed of many different types of cellular and non-cellular factors, mainly including cancer-associated fibroblasts, tumor-associated macrophages, vascular endothelial cells, myeloid-derived suppressor cells and immune cells, all of which can affect the diagnosis, prognosis, and therapeutic efficacy of breast cancer. Importantly, the biological processes occurred in TME, such as angiogenesis, immune evasion, invasion, migration, and the recruition of stromal and tumor-infiltrating cells are under the modulation of c-MYC. These findings indicated that c-MYC serves as a critical regulator of TME. Here, we aimed to summarize and review the relevant research, thus to clarify c-MYC is a key mediator between breast cancer cells and TME. Video Abstract.

Mechanisms driving the immunoregulatory function of cancer cells

Tumours display an astonishing variation in the spatial distribution, composition and activation state of immune cells, which impacts their progression and response to immunotherapy. Shedding light on the mechanisms that govern the diversity and function of immune cells in the tumour microenvironment will pave the way for the development of more tailored immunomodulatory strategies for the benefit of patients with cancer. Cancer cells, by virtue of their paracrine and juxtacrine communication mechanisms, are key contributors to intertumour heterogeneity in immune contextures. In this Review, we discuss how cancer cell-intrinsic features, including (epi)genetic aberrations, signalling pathway deregulation and altered metabolism, play a key role in orchestrating the composition and functional state of the immune landscape, and influence the therapeutic benefit of immunomodulatory strategies. Moreover, we highlight how targeting cancer cell-intrinsic parameters or their downstream immunoregulatory pathways is a viable strategy to manipulate the tumour immune milieu in favour of antitumour immunity.

Role of mitochondrial metabolism in immune checkpoint inhibitors-related myocarditis

Background

Immune checkpoint inhibitor-related myocarditis is the deadliest complication of immunotherapy. However, the underlying pathophysiological mechanisms of its occurrence and development remain unclear. Due to the long-term lack of effective early diagnosis and treatment options, it is of great significance to understand the pathophysiological mechanism of immune checkpoint inhibitor-related myocarditis.

Methods

Tissue samples from three patients with immune checkpoint inhibitor-related myocarditis and three control tissue samples were collected for protein analysis. Differentially expressed proteins were screened out using quantitative proteomics technology based on TMT markers. Protein-protein interaction (PPI) and Gene Ontology (GO) functional enrichment analyses of cross-factors were subsequently performed. Combined with the PD-L1 subcellular organelle- level protein interaction network, we searched for hub proteins involved in immune checkpoint inhibitor-related myocarditis and explored potential drug sensitivity and disease correlation.

Results

A total of 306 differentially expressed proteins were identified in immune checkpoint inhibitor-related myocarditis. Enrichment analysis showed that the differentially expressed proteins were closely related to mitochondrial metabolism. By analyzing mitochondria-related proteins and PD-L1-related proteins, we found four hub proteins, mammalian target of rapamycin (mTOR), Glycogen synthase kinase 3β (GSK3β), Protein tyrosine phosphatase non-receptor type 11 (PTPN11), and Mitofusin 2 (MFN2), indicating that they are closely related to immune checkpoint inhibitor-related myocarditis. Finally, we explored potential drugs for the treatment of immune checkpoint inhibitor-related myocarditis.

Conclusion

Mitochondrial metabolism is involved in the process of immune checkpoint inhibitor-related myocarditis, and we identified four hub proteins, which may become new biomarkers for the early diagnosis and treatment of immune checkpoint inhibitor-related myocarditis.

Prognostic Implications of the Residual Tumor Microenvironment after Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Patients without Pathological Complete Response

With a high risk of relapse and death, and a poor or absent response to therapeutics, the triple-negative breast cancer (TNBC) subtype is particularly challenging, especially in patients who cannot achieve a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). Although the tumor microenvironment (TME) is known to influence disease progression and the effectiveness of therapeutics, its predictive and prognostic potential remains uncertain. This work aimed to define the residual TME profile after NAC of a retrospective cohort with 96 TNBC patients by immunohistochemical staining (cell markers) and chromogenic in situ hybridization (genetic markers). Kaplan-Meier curves were used to estimate the influence of the selected TME markers on five-year overall survival (OS) and relapse-free survival (RFS) probabilities. The risks of each variable being associated with relapse and death were determined through univariate and multivariate Cox analyses. We describe a unique tumor-infiltrating immune profile with high levels of lymphocytes (CD4, FOXP3) and dendritic cells (CD21, CD1a and CD83) that are valuable prognostic factors in post-NAC TNBC patients. Our study also demonstrates the value of considering not only cellular but also genetic TME markers such as MUC-1 and CXCL13 in routine clinical diagnosis to refine prognosis modelling.

Triple negative breast cancer: Immunogenicity, tumor microenvironment, and immunotherapy

Triple negative breast cancer (TNBC) is a biologically diverse subtype of breast cancer characterized by genomic and transcriptional heterogeneity and exhibiting aggressive clinical behaviour and poor prognosis. In recent years, emphasis has been placed on the identification of mechanisms underlying the complex genomic and biological profile of TNBC, aiming to tailor treatment strategies. High immunogenicity, specific immune activation signatures, higher expression of immunosuppressive genes and higher levels of stromal Tumor Infiltrating Lymphocytes, constitute some of the key elements of the immune driven landscape associated with TNBC. The unprecedented response of TNBC to immunotherapy has undoubtedly changed the standard of care in this disease both in the early and the metastatic setting. However, the extent of interplay between immune infiltration and mutational signatures in TNBC is yet to be fully unravelled. In the present review, we present clinical evidence on the immunogenicity and tumour microenvironment influence on TNBC progression and the current treatment paradigms in TNBC based on immunotherapy.

Mechanisms and Strategies to Overcome PD-1/PD-L1 Blockade Resistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is characterized by a high rate of systemic metastasis, insensitivity to conventional treatment and susceptibility to drug resistance, resulting in a poor patient prognosis. The immune checkpoint inhibitors (ICIs) represented by antibodies of programmed death receptor 1 (PD-1) and programmed death receptor ligand 1 (PD-L1) have provided new therapeutic options for TNBC. However, the efficacy of PD-1/PD-L1 blockade monotherapy is suboptimal immune response, which may be caused by reduced antigen presentation, immunosuppressive tumor microenvironment, interplay with other immune checkpoints and aberrant activation of oncological signaling in tumor cells. Therefore, to improve the sensitivity of TNBC to ICIs, suitable patients are selected based on reliable predictive markers and treated with a combination of ICIs with other therapies such as chemotherapy, radiotherapy, targeted therapy, oncologic virus and neoantigen-based therapies. This review discusses the current mechanisms underlying the resistance of TNBC to PD-1/PD-L1 inhibitors, the potential biomarkers for predicting the efficacy of anti-PD-1/PD-L1 immunotherapy and recent advances in the combination therapies to increase response rates, the depth of remission and the durability of the benefit of TNBC to ICIs.

A prognosis marker MUC1 correlates with metabolism and drug resistance in bladder cancer: a bioinformatics research

Background

MUC1 is a type I transmembrane protein that plays an important role in tumor cell signal transduction. Although current studies have shown that MUC1 is upregulated in bladder cancer (BC), the specific mechanism is still unclear.

Methods

We performed expression analysis, gene set enrichment analysis, survival analysis, immune infiltration analysis, drug sensitivity analysis, and metabolism-related gene expression analysis on TCGA-BLCA, GES31684 and GSE13507.

Results

The expression of MUC1 in the tumor and lymphatic metastasis positive samples was significantly increased. Genes related to MUC1 expression were significantly enriched in immune response, ribosomes, exosomes, and energy metabolism. The results of the immune infiltration analysis showed that M1 macrophages in BC with high MUC1 expression were significantly decreased. Expression of MUC1 increases drug resistance in BC patients. In addition, MUC1 increases glycolysis, glucose uptake, and lactate production by inducing metabolic reprogramming.

Conclusion

MUC1 has a significant effect on the metabolism and immune cell infiltration of BC, which may be the cause of increased drug resistance, and can be used as a molecular target for the diagnosis and treatment of BC.

A ferroptosis-related gene signature associated with immune landscape and therapeutic response in osteosarcoma

BACKGROUND

The role of ferroptosis in tumor progression and immune microenvironment is extensively investigated. However, the potential value of ferroptosis regulators in predicting prognosis and therapeutic strategies for osteosarcoma (OS) patients remains to be elucidated.

METHODS

Here, we extracted transcriptomic and survival data from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) to investigate the expression and prognostic value of ferroptosis regulators in OS patients. After comprehensive analyses, including Gene set variation analysis (GSVA), single-sample gene-set enrichment analysis (ssGSEA), Estimated Stromal and Immune cells in Malignant Tumor tissues using Expression (ESTIMATE), single-cell RNA sequencing, and biological experiments, our constructed 8-ferroptosis-regulators prognostic signature effectively predicted the immune landscape, prognosis, and chemoradiotherapy strategies for OS patients.

RESULTS

We constructed an 8-ferroptosis-regulators signature that could predict the survival outcome of OS. The signature algorithm scored samples, and high-scoring patients were more prone to worse prognoses. The tumor immune landscape suggested the positive relevance between risk score and immunosuppression. Interfering HILPDA and MUC1 expression would inhibit tumor cell proliferation and migration, and MUC1 might improve the ferroptosis resistance of OS cells. Moreover, we predicted chemoradiotherapy strategies of cancer patients following ferroptosis-risk-score groups.

CONCLUSION

Dysregulated ferroptosis gene expression can affect OS progression by affecting the tumor immune landscape and ferroptosis resistance. Our risk model can predict OS survival outcomes, and we propose that HILPDA and MUC1 are potential targets for cancer therapy.