Targeting the complexity of ERBB2 biology in gastroesophageal carcinoma

Promotion of stem cell-like phenotype of lung adenocarcinoma by FAM83A via stabilization of ErbB2

Lung cancer stands as the leading cause of mortality among all types of tumors, with over 40% of cases being lung adenocarcinoma (LUAD). Family with sequence similarity 83 member A (FAM83A) emerges as a notable focus due to its frequent overexpression in LUAD. Despite this, the precise role of FAM83A remains elusive. This study addresses this gap by unveiling the crucial involvement of FAM83A in maintaining the cancer stem cell-like (CSC-like) phenotype of LUAD. Through a global proteomics analysis, the study identifies human epidermal growth factor receptor 2 (HER2 or ErbB2) as a crucial target of FAM83A. Mechanistically, FAM83A facilitated ErbB2 expression at the posttranslational modification level via the E3 ubiquitin ligase STUB1 (STIP1-homologous U-Box containing protein 1). More importantly, the interaction between FAM83A and ErbB2 at Arg241 promotes calcineurin (CALN)-mediated dephosphorylation of ErbB2, followed by inhibition of STUB1-mediated ubiquitin-proteasomal ErbB2 degradation. The maintenance of the CSC-like phenotype by FAM83A, achieved through the posttranslational regulation of ErbB2, offers valuable insights for identifying potential therapeutic targets for LUAD.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

Identification of three lncRNA-related prognostic signatures in gastric cancer by integrated multi-omics analysis

Aims: The systematic identification of molecular features correlated with the clinical status of gastric cancer (GC) in patients is significant, although such investigation remains insufficient. Methods: GC subtyping based on RNA sequencing, copy number variation and DNA methylation data were derived from The Cancer Genome Atlas program. Prognostics lncRNA biomarkers for GC were identified by univariate Cox, LASSO and SVM-RFE analysis. Results: Three molecular subtypes with significant survival discrepancies, and their specific DEmRNAs and DElncRNAs were identified. Three reliable prognostic-associated lncRNA, including LINC00670, LINC00452 and LINC00160, were selected for GC. Conclusion: Our findings expanded the understanding on the regulatory network of lncRNAs in GC, providing potential targets for prognosis and treatment of GC patients.

Detailed curriculum vitae of HER2-targeted therapy

With the booming development of precision medicine, molecular targeted therapy has been widely used in clinical oncology treatment due to a smaller number of side effects and its superior accuracy compared to that of traditional strategies. Among them, human epidermal growth factor receptor 2 (HER2)-targeted therapy has attracted considerable attention and has been used in the clinical treatment of breast and gastric cancer. Despite excellent clinical effects, HER2-targeted therapy remains in its infancy due to its resulting inherent and acquired resistance. Here, a comprehensive overview of HER2 in numerous cancers is presented, including its biological role, involved signaling pathways, and the status of HER2-targeted therapy.

Current developments in gastric cancer: from molecular profiling to treatment strategy

Gastric cancer and gastro-oesophageal junction cancer represent a global health-care challenge. Despite the efficacy of improved chemotherapy and surgical options, these patients still have a poor prognosis. In advanced disease, only trastuzumab and some immune checkpoint inhibitors, such as nivolumab and pembrolizumab in addition to chemotherapy, have demonstrated consistent and reliable efficacy in patients with HER2-positive and PDL1-positive tumours, respectively. In this Review, we discuss the intrinsic characteristics of gastric and gastro-oesophageal cancer from the molecular and clinical perspectives and provide a comprehensive review of previously reported and ongoing phase II and III clinical trials with targeted agents and immunotherapy in advanced and localized settings. Finally, we suggest alternative strategies to help overcome current challenges in precision medicine and to improve outcomes for these patients.

Adding of apatinib and camrelizumab to overcome de novo trastuzumab resistance of HER2-positive gastric cancer: A case report and literature review

Background: Studies confirmed that trastuzumab plus fluorouracil-based chemotherapy improves the survival to more than 1 year in human with human epidermal growth factor receptor-2 (HER2)-positive advanced gastric cancer. However, there are still a small proportion of patients who do not benefit from trastuzumab treatment. Case summary: Here, we described a case report of de novo trastuzumab resistance in HER2-positive gastric cancer. Concomitant cyclin-E1 (CCNE1) and HER2 amplification are associated with de novo trastuzumab resistance. Genomic analysis demonstrated CCNE1 amplification and TP53 mutation in a HER2-positive gastric cancer patient. This patient achieved significant survival benefit and good safety when the patient received triple regimens consisting of trastuzumab, apatinib, and camrelizumab. Conclusion: Trastuzumab plus camrelizumab plus apatinib has the potential efficacy in HER2-positive gastric cancer patients who were previously treated with trastuzumab plus chemotherapy. This may lead to a new solution to trastuzumab resistance.

Patients with positive HER-2 amplification advanced gastroesophageal junction cancer achieved complete response with combined chemotherapy of AK104/cadonilimab (PD-1/CTLA-4 bispecific): A case report

Background

Human epidermal growth factor receptor 2 (HER2) is the most prominent therapeutic target for advanced gastric (G)/GEJ cancer. However, targeted therapy did not significantly improve survival. Currently, there are no regimens for the treatment of HER-2 amplification that exclude targeted agents.

Case presentation

A 42-year-old man was diagnosed with adenocarcinoma of GEJ (stage IV) with liver metastasis and lung metastasis. The patient was enrolled in a trial that excluded patients with known HER2-positivity: AK104, a PD-1/CTLA-4 bispecific antibody, combined with chemotherapy (mXELOX) as first-line therapy for advanced gastric G/GEJ cancer (NCT03852251). After six cycles of AK104 combined with chemotherapy therapy, immune-related pulmonary toxicity was observed. We rechallenged AK104 after hormone therapy, and no further pulmonary toxicity was observed. Immune-related hepatitis occurred in the patient during immunotherapy combined with single-drug capecitabine therapy. After combining steroid therapy with mycophenolate mofetil, the patient's immune hepatitis improved. Nevertheless, the patient was excluded from the clinical study due to the long-term absence of medication. Antitumor therapy was also discontinued in view of the patient's adverse immune response. The patient did not receive subsequent immune antitumor therapy, and immune-related hepatitis still occurred intermittently, but the disease evaluation was maintained at PR. A complete response was confirmed by PET/CT and the biopsy specimen from gastroscopy on 2020-06-10. Next generation sequencing of biopsy tissue was used to guide subsequent therapy at a recent follow-up visit. The results indicated that ERBB2 mutations occurred at copy number 58.4934 (HER-2), TMB = 3.1, MSS. IHC: EBV (-), PD-L1 CPS = 3, HER-2 (3+).

Conclusion

Patients with HER-2-positive advanced GEJ cancer received PD-1/CTLA-4 bispecific immunotherapy combined with chemotherapy and achieved complete remission. It offers a novel, highly specific, and highly potent therapeutic option for HER-2-positive patients. Its use should be considered as a new treatment when trastuzumab is not viable. Currently, we are working to overcome this resistance.

Emerging Role of ERBB2 in Targeted Therapy for Metastatic Colorectal Cancer: Signaling Pathways to Therapeutic Strategies

Despite recent improvements in the comprehensive therapy of malignancy, metastatic colorectal cancer (mCRC) continues to have a poor prognosis. Notably, 5% of mCRC cases harbor Erb-B2 receptor tyrosine kinase 2 (ERBB2) alterations. ERBB2, commonly referred to as human epidermal growth factor receptor 2, is a member of the human epidermal growth factor receptor family of protein tyrosine kinases. In addition to being a recognized therapeutic target in the treatment of gastric and breast malignancies, it is considered crucial in the management of CRC. In this review, we describe the molecular biology of ERBB2 from the perspective of biomarkers for mCRC-targeted therapy, including receptor structures, signaling pathways, gene alterations, and their detection methods. We also discuss the relationship between ERBB2 aberrations and the underlying mechanisms of resistance to anti-EGFR therapy and immunotherapy tolerance in these patients with a focus on novel targeted therapeutics and ongoing clinical trials. This may aid the development of a new standard of care in patients with ERBB2-positive mCRC.