HER2 in Metastatic Colorectal Cancer: Pathology, Somatic Alterations, and Perspectives for Novel Therapeutic Schemes

Targeting the HER2-ELF3-KRAS axis: a novel therapeutic strategy for KRASG13D colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent cancers worldwide, with KRAS mutations playing a significant role in its tumorigenesis. Among the KRAS variants, the G13D mutation is associated with poor prognosis and distinctive biological behaviors. This study focuses on the role of HER2, a critical prognostic and predictive biomarker, in modulating the unique characteristics of KRASG13D-mutated CRCs. We identified a novel transcriptional regulatory network involving HER2, ELF3, and KRAS, with ELF3 acting as a key transcription factor (TF) that regulates KRAS expression under conditions of HER2 overexpression. Our findings reveal that this HER2-ELF3-KRAS axis is exclusively activated in KRASG13D, driving aggressive oncogenic features and conferring resistance to cetuximab (CTX) therapy. Through comprehensive analysis of gene expression profiles, we demonstrated that HER2 is a crucial therapeutic target specifically for KRASG13D CRCs. To explore this further, we introduced YK1, a small molecule inhibitor designed to disrupt the ELF3-MED23 interaction, leading to the transcriptional downregulation of HER2 and KRAS. This intervention significantly attenuated the HER2-ELF3-KRAS axis, sensitizing KRASG13D CRCs to CTX and reducing their tumorigenic potential by inhibiting the epithelial-to-mesenchymal transition process. Our study underscores the importance of HER2 as a key determinant in the unique biological characteristics of KRASG13D CRCs and highlights the therapeutic potential of targeting the HER2-ELF3-KRAS axis. By presenting YK1 as a novel pharmacological approach, we provide a promising strategy for developing tailored interventions for KRASG13D CRCs, contributing to the ongoing efforts in precision medicine for CRCs.

HER2-targeted therapy in colorectal cancer: a comprehensive review

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths worldwide. Despite treatment advancements in the last decades, CRC remains heterogeneous with significant clinical and genetic diversity. Human epidermal growth factor receptor 2 (HER2) proto-oncogene plays a critical role, as its amplification or overexpression leading to abnormal cell proliferation and tumorigenesis. HER2 overexpression or amplification is identified in 2-4% of metastatic CRCs (mCRC) patients, representing a potential therapeutic target. It is also associated with resistance against epidermal growth factor receptor (EGFR)-targeted therapies like cetuximab and panitumumab, for treatment of RAS wild-type mCRC. Although HER2-positive mCRC is rare, assessing HER2 levels is important. Furthermore, anti-HER2 therapies exhibited non-toxic profile and high efficacy in chemorefractory cases. This review delves into modern management of anti-HER2 therapies in CRC with a particular focus on recent advances and current knowledge about the prognostic and predictive value of HER2.

Synthesis and biological assessment of chalcone and pyrazoline derivatives as novel inhibitor for ELF3-MED23 interaction

HER2 overexpression significantly contributes to the aggressive nature and recurrent patterns observed in various solid tumors, notably gastric cancers. Trastuzumab, HER2-targeting monoclonal antibody drug, has shown considerable clinical success; however, readily emerging drug resistance emphasizes the pressing need for improved interventions in HER2-overexpressing cancers. To address this, we proposed targeting the protein-protein interaction (PPI) between ELF3 and MED23 as an alternative therapeutic approach to trastuzumab. In this study, we synthesized a total of 26 compounds consisting of 10 chalcones, 7 pyrazoline acetyl, and 9 pyrazoline propionyl derivatives, and evaluated their biological activity as potential ELF3-MED23 PPI inhibitors. Upon systematic analysis, candidate compound 10 was selected due to its potency in downregulating reporter gene activity of ERBB2 promoter confirmed by SEAP activity and its effect on HER2 protein and mRNA levels. Compound 10 effectively disrupted the binding interface between the ELF3 TAD domain and the 391-582 amino acid region of MED23, resulting in successful inhibition of the ELF3-MED23 PPI. This intervention led to a substantial reduction in HER2 levels and its downstream signals in the HER2-positive gastric cancer cell line. Subsequently, compound 10 induced significant apoptosis and anti-proliferative effects, demonstrating superior in vitro and in vivo anticancer activity overall. We found that the anticancer activity of compound 10 was not only restricted to trastuzumab-sensitive cases, but was also valid for trastuzumab-refractory clones. This suggests its potential as a viable therapeutic option for trastuzumab-resistant gastric cancers. In summary, compound 10 could be a novel alternative therapeutic strategy for HER2-overexpressing cancers, overcoming the limitations of trastuzumab.

Clinical significance of Talin-1 and HER-2 status in different types of gastric carcinoma

BACKGROUND

Talin-1 (TLN1) is crucial in cell migration, metastasis, and cancer development. This study evaluated Talin-1 expression and its clinical significance in gastric cancer (GC), along with human epidermal growth factor receptor-2 (HER-2) expression and its correlation with Talin-1.

METHODS

Bioinformatics analysis assessed the potential prognostic value of Talin-1 and HER-2 in GC patients. The study included 223 GC patients (Signet Ring Cells and Intestinal subtypes) and 29 non-malignant tissue samples. Immunohistochemistry (IHC) on tissue microarray slides evaluated Talin-1 and HER-2 expression and clinical significance. Receiver operating characteristic (ROC) curves assessed their diagnostic value.

RESULTS

Bioinformatics identified Talin-1 as a potential prognostic factor and HER-2 as an oncogene in GC. Talin-1 and HER-2 expression increased in SRC-type GC samples compared to non-malignant tissues. High cytoplasmic Talin-1 expression inversely correlated with tumor expansion and invasion in SRC-type GC. Increased HER-2 expression positively correlated with metastasis. ROC curves showed significant diagnostic values for both proteins.

CONCLUSIONS

Higher cytoplasmic Talin-1 expression is associated with less invasive tumor behavior, while increased membranous HER-2 expression is associated with metastasis in SRC-type GC. These findings suggest potential use in assessing diagnosis and screening high-risk cancer patients, particularly those with SRC-type GC.

Prognostic and Predictive Roles of HER2 Status in Non-Breast and Non-Gastroesophageal Carcinomas

The oncogene ERBB2, also known as HER2 or c-ERB2, is located on chromosome 17 (q12). It encodes a tyrosine kinase receptor, the human epidermal growth factor receptor 2 (HER2), involved in neoplastic proliferation, tumor angiogenesis, and invasiveness. Over the past years, the introduction of various anti-HER2 therapies has significantly improved outcomes for patients with HER2-positive breast and gastroesophageal carcinomas. More recently, the introduction of a new antibody-drug conjugate, that is trastuzumab deruxtecan, expanded the therapeutic options to low-HER2 breast and gastroesophageal tumors. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers. We critically analyzed the key published studies, focusing on utilized scoring systems and assays used, and analyzed clinical parameters and therapeutic approaches. Although the evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal has been widely increasing over the last decade, it still remains investigational, revealing a tumor site-related prognostic and predictive value of the different types of HER2 alterations. However, standardized and validated scoring system assays have not been well-established for many organs.

Anti-angiogenesis in colorectal cancer therapy

The morbidity of colorectal cancer (CRC) has risen to third place among malignant tumors worldwide. In addition, CRC is a common cancer in China whose incidence increases annually. Angiogenesis plays an important role in the development of tumors because it can bring the nutrients that cancer cells need and take away metabolic waste. Various mechanisms are involved in the formation of neovascularization, and vascular endothelial growth factor is a key mediator. Meanwhile, angiogenesis inhibitors and drug resistance (DR) are challenges to consider when formulating treatment strategies for patients with different conditions. Thus, this review will discuss the molecules, signaling pathways, microenvironment, treatment, and DR of angiogenesis in CRC.

Biomarker discovery and validation for gastrointestinal tumors: A comprehensive review of colorectal, gastric, and liver cancers

Gastrointestinal (GI) malignancies, encompassing gastric, hepatic, colonic, and rectal cancers, are prevalent forms of cancer globally and contribute substantially to cancer-related mortality. Although there have been improvements in methods for diagnosing and treating GI cancers, the chances of survival for these types of cancers are still extremely low. According to the World Cancer Research International Fund's most recent figures, stomach cancer was responsible for roughly one million deaths worldwide in 2020. This emphasizes the importance of developing more effective tools for detecting, diagnosing, and predicting the outcome of these cancers at an early stage. Biomarkers, quantitative indications of biological processes or disease states, have emerged as promising techniques for enhancing the diagnosis and prognosis of GI malignancies. Recently, there has been a considerable endeavor to discover and authenticate biomarkers for various GI cancers by the utilization of diverse methodologies, including genomics, proteomics, and metabolomics. This review provides a thorough examination of the current state of biomarker research in the field of gastrointestinal malignancies, with a specific emphasis on colorectal, stomach, and liver cancers. A thorough literature search was performed on prominent databases such as PubMed, Scopus, and Web of Science to find pertinent papers published until November, 2023 for the purpose of compiling this review. The diverse categories of biomarkers, encompassing genetic, epigenetic, and protein-based biomarkers, and their potential utility in the fields of diagnosis, prognosis, and treatment selection, are explored. Recent progress in identifying and confirming biomarkers, as well as the obstacles that persist in employing biomarkers in clinical settings are emphasized. The utilization of biomarkers in GI cancers has significant potential in enhancing patient outcomes. Ongoing research is expected to uncover more efficient biomarkers for the diagnosis and prognosis of these cancers.

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

A HER2-targeting antibody-MMAE conjugate RC48 sensitizes immunotherapy in HER2-positive colon cancer by triggering the cGAS-STING pathway

Human epidermal growth factor receptor 2 (HER2) is a protein that is overexpressed in some types of cancer, including breast and urothelial cancer. Here we found that HER2 was present in a portion of colon cancer patients, raising the possibility of using anti-HER2 therapy. RC48, a novel antibody-drug conjugate (ADC) comprising cytotoxic monomethyl auristatin E (MMAE) and an anti-HER2 antibody tethered via a linker, showed a comparable therapeutic effect in both HER2 low expressed (IHC2+/FISH- or IHC+) and high expressed urothelial cancer patients. In vitro studies using colon cancer cell lines showed that RC48 effectively impeded the proliferation of HER2-positive cells, indicating its potential as a treatment for HER2-positive colon cancer. Mechanism study showed that RC48 not only induces cell cycle arrest but also disrupts HER2-mediated restain of cGAS-STING signaling, potentially activating an immune response against the cancer cells. The administration of RC48 significantly reduced the growth of HER2-positive colon cancer and made HER2-positive colon cancer cells more susceptible to immunotherapy. The results of our study will contribute to determining the feasibility of RC48 as a therapeutic option for HER2-positive colon cancer.

The Value of Prolactin, a Panel of Cytokines, and the Soluble Human Epidermal Growth Factor Receptor 2 in the Prediction of Rapid Progression and Shorter Survival during Palliative Chemotherapy of Colorectal Cancer Patients

The prediction of colorectal cancer (CRC) response to palliative chemotherapy (CTH) is still difficult. Patients at a higher risk of progression may benefit from more aggressive treatment. This study assessed the predictive value of prolactin (PRL) and a panel of cytokines, chemokines, and growth factors for the risk of rapid progression in CRC patients starting palliative CTH. This study included 51 CRC patients initiating palliative CTH with up to 5-year follow-up, divided into rapid and non-rapid progressors. Serum samples were collected before CTH for assessment of a large panel of cytokines, chemokines, growth factors, and PRL via a multiplex method. Rapid progressors (N = 19) were characterized by increased baseline values of IL-8 and IP10 but decreased PRL levels. In addition, PRL below 18.2 ng/mL was a strong predictor of weight loss during CTH. Grade 3 (HR = 2.97; 95%CI: 1.48-5.98) and PRL level (HR = 0.96; 95%CI: 0.91-1.01) were independent risk factors of progression. We showed that CRC rapid progressors are characterized by decreased baseline PRL levels. In addition, increased baseline levels of IP-10, sHER-2, IL-6, and IL-8 may be associated with longer survival; however, larger studies are needed to confirm their predictive role in CRC patients.

Cancer Vaccines: From the State of the Art to the Most Promising Frontiers in the Treatment of Colorectal Cancer

Colorectal cancer represents 10% of all new cancer cases each year and accounts for almost 10% of all cancer deaths. According to the WHO, by 2040 there will be a 60% increase in colorectal cancer cases. These data highlight the need to explore new therapeutic strategies. Classical interventions include surgical resection, chemotherapy and radiotherapy, which are invasive strategies that have many side effects on the patients and greatly affect their quality of life. A great advance in the treatment of this cancer type, as well as of all the others, could be the development of a vaccination strategy preventing the onset, the progression or the relapse of the pathology. In this review, we summarize the main vaccination strategies that are being studied for the treatment of colorectal cancer (CRC) and finally explore the possibility of using B-cells for the development of a new type of vaccine.

Cell Therapy as Target Therapy against Colon Cancer Stem Cells

Cancer stem cells (CSCs) are a small subpopulation of cells within tumors with properties, such as self-renewal, differentiation, and tumorigenicity. CSCs have been proposed as a plausible therapeutic target as they are responsible for tumor recurrence, metastasis, and conventional therapy resistance. Selectively targeting CSCs is a promising strategy to eliminate the propagation of tumor cells and impair overall tumor development. Recent research shows that several immune cells play a crucial role in regulating tumor cell proliferation by regulating different CSC maintenance or proliferation pathways. There have been great advances in cellular immunotherapy using T cells, natural killer (NK) cells, macrophages, or stem cells for the selective targeting of tumor cells or CSCs in colorectal cancer (CRC). This review summarizes the CRC molecular profiles that may benefit from said therapy and the main vehicles used in cell therapy against CSCs. We also discuss the challenges, limitations, and advantages of combining conventional and/or current targeted treatments in the late stages of CRC.

Somatic mutation profiling, tumor-infiltrating leukocytes, tertiary lymphoid structures and PD-L1 protein expression in HER2-amplified colorectal cancer

The status of human epidermal growth factor receptor 2 (HER2) for the prognosis in colorectal cancer (CRC) is controversial, and the characteristics of the somatic mutation spectrum, tumor-infiltrating leukocytes, tertiary lymphoid structures and PD-L1 protein are unknown in HER2-amplified colorectal cancer (HACC). In order to explore these characteristics along with their correlation with clinicopathological factors and prognosis in HACC. Samples of 812 CRC patients was collected. After immunohistochemistry (IHC), 59 of 812 were found to be HER2-positive, then 26 of 59 samples were further determined to be HER2 amplification by fluorescence in situ hybridization (FISH). Somatic mutation profiling of HACC was analysed using whole exome sequencing (WES). Multiplex fluorescence immunohistochemistry (mIHC) was used for tumor-infiltrating leukocytes and tertiary lymphoid structures (TLSs), while PD-L1 protein was detected by IHC. Our results indicate that the detection rates of HER2 positivity by IHC and FISH were 7.3% and 3.2% respectively, and HER2 amplification is correlated with distant tumour metastasis. The somatic mutation profiling revealed no differences between HACC and HER2-negative CRC. However, TP 53 strongly correlated with poor prognosis in HACC. Furthermore, tumor-infiltrating T cells and TLSs in the tumor immune microenvironment, as well as PD-L1 expression, were higher in HACC than in HER2-negative controls. However, none of them were associated with the prognosis of HACC. In all, HER2 amplification is correlated with distant metastasis and TP53 gene mutation may be a potential protective mechanism of HACC.