HER2 promotes epithelial-mesenchymal transition through regulating osteopontin in gastric cancer

Advances in HER2-Targeted Therapies: From monoclonal antibodies to dual inhibitors developments in cancer treatment

HER2 receptors, overexpressed in certain human cancers, have drawn significant attention in cancer research due to their correlation with poor survival rates. Researchers have developed monoclonal antibodies like Trastuzumab and Pertuzumab against HER2 receptors, which have proven highly beneficial in cancer therapy. Bispecific antibodies like Zanidatamab and antibody-drug conjugates like T-DM1 have been developed to overcome the resistance associated with monotherapy. Small molecules such as Lapatinib, Neratinib, and Pyrotinib were initially developed for treating breast cancer. However, ongoing research is investigating their potential use in other types of cancer, often in combination with other medications. EGFR/HER2 dual-targeted drugs have overcome drug resistance associated with HER2-targeted monotherapy. This comprehensive review covers the structural characteristics of HER2, the HER family signaling pathway mechanism, recent findings regarding HER2 receptor involvement in various cancers, and diverse HER2-targeted therapies. This information provides a comprehensive understanding of HER2-targeted strategies in the evolving field of cancer treatment.

HER-2 positive gastric cancer: Current targeted treatments

Gastric cancer (GC) is highly metastatic and characterized by HER2 amplification. Aberrant HER2 expression drives metastasis, therapy resistance, and tumor recurrence. HER2 amplification contributes to drug resistance by upregulating DNA repair enzymes and drug afflux proteins, reducing drug efficacy. HER2 modulates transcription factors critical for cancer stem cell properties, further impacting drug resistance. HER2 activity is influenced by HER-family ligands, promoting oncogenic signaling. These features point to HER2 as a targetable driver in GC. This review outlines recent advances in HER2-mediated mechanisms and their upstream and downstream signaling pathways in GC. Additionally, it discusses preclinical research investigation that comprehends trastuzumab-sensitizing phytochemicals, chemotherapeutics, and nanoparticles as adjunct therapies. These developments hold promise for improving outcomes and enhancing the management of HER2-positive GC.

HER2 Alterations in Non-Small Cell Lung Cancer: Biologico-Clinical Consequences and Interest in Therapeutic Strategies

Lung cancer stands as the first cause of death by cancer in the world. Despite the improvement in patients' outcomes in the past decades through the development of personalized medicine approaches, a substantial portion of patients remains ineligible for targeted therapies due to the lack of a "druggable" molecular target. HER2, a receptor tyrosine kinase member of the EGFR/ErbB family, is known to show oncogenic properties. In this review, we focus on the different HER2 dysregulation mechanisms that have been observed in non-small cell lung cancer (NSCLC): gene mutation, gene amplification, protein overexpression and protein hyper-phosphorylation, the latter suggesting that HER2 dysregulation can occur independently of any molecular aberration. These HER2 alterations inevitably have consequences on tumor biology. Here, we discuss how they are not only involved in abnormal proliferation and survival of cancer cells but also potentially in increased angiogenic properties, mesenchymal features and tumor immune escape. Finally, we review the impact of these HER2 alterations in various therapeutic approaches. While standard chemotherapy and groundbreaking immunotherapy seem rather ineffective for HER2-altered NSCLCs, the development of HER2-targeted therapies such as tyrosine kinase inhibitors, anti-HER2 antibodies and especially antibody-drug conjugates could provide new hopes for patients.

HRCT1, negatively regulated by miR-124-3p, promotes tumor metastasis and the growth of gastric cancer by activating the ERBB2-MAPK pathway

BACKGROUND

Gastric cancer is the fourth leading cause of cancer-related deaths worldwide. And patient outcomes are poor due to tumor relapse and metastasis. To develop new therapeutic strategies, it is of great importance to explore the mechanism underlying the progression of gastric cancer.

METHODS

Primary gastric cancer samples with lymph node metastases (LNM) and without LNM were subjected to mRNA microarray assay. The differentially expressed genes were confirmed by RT-qPCR. HRCT1 protein expression was further detected using an immunohistochemistry (IHC) assay. In vitro and in vivo assays were performed to investigate the role of HRCT1 in tumor invasion, metastasis, and proliferation. The expressions of the downstream target genes of HRCT1 were detected by microarray, RT-qPCR and Western blot assays. Dual-luciferase reporter and Western blot assays were carried out to identify miRNAs target to HRCT1.

RESULTS

HRCT1 was upregulated in gastric cancer, and high expression of HRCT1 was associated with poor overall survival (OS) and disease-free survival (DFS). Moreover, HRCT1protein expression was an independent predictor for poor OS and DFS. HRCT1 could promote gastric cancer cells' migration, invasion, and proliferation in vitro as well as tumor metastasis and growth in vivo. Notably, our data showed that HRCT1 promoted gastric cancer progression by activating the ERBB2-MAPK signaling pathway. At least partially, the expression of HRCT1 could be negatively regulated by miR-124-3p.

CONCLUSIONS

The upregulated expression of HRCT1 predicts poor survival for patients with gastric cancer. HRCT1 promotes tumor progression by activating the ERBB2-MAPK pathway. HRCT1, negatively regulated by miR-124-3p, may be a potential therapeutic target for patients with gastric cancer.

Construction of targeted 10B delivery agents and their uptake in gastric and pancreatic cancer cells

Boron Neutron Capture Therapy (BNCT) is a new binary radiation therapy for tumor tissue, which kills tumor cells with neutron capture reaction. Boron neutron capture therapy has become a technical means for glioma, melanoma, and other diseases has been included in the clinical backup program. However, BNCT is faced with the key problem of developing and innovating more efficient boron delivery agents to solve the targeting and selectivity. We constructed a tyrosine kinase inhibitor-L-p-boronophenylalanine (TKI-BPA) molecule, aiming to improve the selectivity of boron delivery agents by conjugating targeted drugs while increasing the molecular solubility by adding hydrophilic groups. It shows excellent selectivity in differential uptake of cells, and its solubility is more than 6 times higher than BPA, leading to the saving of boron delivery agents. This modification method is effective for improving the efficiency of the boron delivery agent and is expected to become a potential alternative with high clinical application value.

Establishment and characterization of a HER2-enriched canine mammary cancerous myoepithelial cell line

BACKGROUND

Canine mammary tumors (CMTs) have a poor prognosis, along with tumor recurrence and metastasis. Cell lines are vital in vitro models for CMT research. Many CMT epithelial cell lines were reported. However, canine mammary myoepithelial cells, the contractile component of the canine mammary tissue were overlooked. This study aimed at establishing such a cell line. CMT-1 cell line was obtained from a canine mammary tumor CMT-1 and characterized molecularly through qPCR, western blotting, immunochemistry and immunofluorescence. Its doubling time, cytogenetic analysis and migration rate were evaluated using growth study, karyotype analysis and wound healing assay respectively. To determine its tumorigenesis, xenograft transplantation was performed.

RESULTS

CMT-1 tumor was a complex canine mammary carcinoma that stained negative to estrogen receptors (ER) and progesterone receptors (PR), but positive to human epidermal growth receptor-2 (HER2), defined as HER2-enriched subtype. In this study, a CMT-1 cell line obtained from CMT-1 tumor was immune-positive to vimentin, α-SMA, p63 and negative to E-cadherin (E-cad), indicating CMT-1 cells were myoepithelial cells. It was successfully cultured for more than 50 passages showing the same immunoreactivity to ER, PR, and HER2 as the primary canine tumor. The doubling time of CMT-1 cell line was 26.67 h. The chromosome number of CMT-1 cells ranged from 31 to 64. A potential spontaneous epithelial to mesenchymal transition (EMT) was noticed during cell cultures. Potential EMT-induced CMT-1 cells showed no significance in migration rate compared to the original CMT-1 cells. CMT-1 cells was able to grow on a 3D culture and formed grape-like, solid, and cystic mammospheres at different time period. Inoculation of CMT-1 cells induced a complex HER2-enriched mammary tumor with metastasis in mice.

CONCLUSIONS

A canine cancerous HER2-enriched myoepithelial cell line was successfully established and a canine mammosphere developed from myoepithelial cells was documented in this study. We are expecting this novel cell line and its associated mammospheres could be used as a model to elucidate the role of myoepithelial cells in CMT carcinogensis in the future.

Cell Fusion-Related Proteins and Signaling Pathways, and Their Roles in the Development and Progression of Cancer

Cell fusion is involved in many physiological and pathological processes, including gamete binding, and cancer development. The basic processes of cell fusion include membrane fusion, cytoplasmic mixing, and nuclear fusion. Cell fusion is regulated by different proteins and signaling pathways. Syncytin-1, syncytin-2, glial cell missing 1, galectin-1 and other proteins (annexins, myomaker, myomerger etc.) involved in cell fusion via the cyclic adenosine-dependent protein kinase A, mitogen-activated protein kinase, wingless/integrase-1, and c-Jun N-terminal kinase signaling pathways. In the progression of malignant tumors, cell fusion is essential during the organ-specific metastasis, epithelial-mesenchymal transformation, the formation of cancer stem cells (CSCs), cancer angiogenesis and cancer immunity. In addition, diploid cells can be induced to form polyploid giant cancer cells (PGCCs) via cell fusion under many kinds of stimuli, including cobalt chloride, chemotherapy, radiotherapy, and traditional Chinese medicine. PGCCs have CSC-like properties, and the daughter cells derived from PGCCs have a mesenchymal phenotype and exhibit strong migration, invasion, and proliferation abilities. Therefore, exploring the molecular mechanisms of cell fusion can enable us better understand the development of malignant tumors. In this review, the basic process of cell fusion and its significance in cancer is discussed.