Application of trastuzumab emtansine in HER-2-positive and KRAS/BRAF-mutated colon cancer cells

The therapeutic effect of traditional Chinese medicine on breast cancer through modulation of the Wnt/β-catenin signaling pathway

Breast cancer, the most prevalent malignant tumor among women globally, is significantly influenced by the Wnt/β-catenin signaling pathway, which plays a crucial role in its initiation and progression. While conventional chemotherapy, the standard clinical treatment, suffers from significant drawbacks like severe side effects, high toxicity, and limited prognostic efficacy, Traditional Chinese Medicine (TCM) provides a promising alternative. TCM employs a multi-targeted therapeutic approach, which results in fewer side effects and offers a high potential for effective treatment. This paper presents a detailed analysis of the therapeutic impacts of TCM on various subtypes of breast cancer, focusing on its interaction with the Wnt/β-catenin signaling pathway. Additionally, it explores the effectiveness of both monomeric and compound forms of TCM in the management of breast cancer. We also discuss the potential of establishing biomarkers for breast cancer treatment based on key proteins within the Wnt/β-catenin signaling pathway. Our aim is to offer new insights into the prevention and treatment of breast cancer and to contribute to the standardization of TCM.

Translational research of new developments in targeted therapy of colorectal cancer

A severe global health concern is the rising incidence and mortality rate of colorectal cancer (CRC). Chemotherapy, which is typically used to treat CRC, is known to have limited specificity and can have noticeable side effects. A paradigm shift in cancer treatment has been brought about by the development of targeted therapies, which has led to the appearance of pharmacological agents with improved efficacy and decreased toxicity. Epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER2), and BRAF are among the molecular targets covered in this review that are used in targeted therapy for CRC. The current discussion also covers advancements in targeted therapeutic approaches, such as antibody-drug conjugates, immune checkpoint inhibitors, and chimeric antigen receptor (CAR) T-cell therapy. A review of the clinical trials and application of these particular therapies in treating CRC is also done. Despite the improvements in targeted therapy for CRC, problems such as drug resistance and patient selection remain to be solved. Despite this, targeted therapies have offered fresh possibilities for identifying and treating CRC, paving the way for the development of personalized medicine and extending the life expectancy and general well-being of CRC patients.

Ado-tratuzumab emtansine beyond breast cancer: therapeutic role of targeting other HER2-positive cancers

Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate approved by the FDA in 2013 for advanced HER2-positive breast cancer treatment exhibiting promising clinical benefits. However, HER2 overexpression and gene amplification have also been reported in other cancers like gastric cancer, non-small cell lung cancer (NSCLC), and colorectal cancer. Numerous preclinical studies have also revealed the significant antitumor effect of T-DM1 on HER2-positive tumors. With the advancement in research, several clinical trials have been conducted to investigate the antitumor effect of T-DM1. In this review, we briefly introduced the pharmacological effects of T-DM1. We reviewed its preclinical and clinical studies, especially on other HER2-positive cancers, establishing what has been encountered between its preclinical and clinical studies. In clinical studies, we found that T-DM1 has a therapeutic value on other cancers. An insignificant effect was observed on gastric cancer and NSCLC, inconsistent with the preclinical studies.

Case Report: A case of advanced duodenal adenocarcinoma in complete remission after chemotherapy combined with targeted therapy and radiotherapy

Duodenal adenocarcinoma (DA) is an extremely rare and highly aggressive malignant tumor of the digestive system. Due to the lack of specific clinical characteristics, it is easy to misdiagnosis and miss diagnosis, and the lack of specific consensus and recommendation for treatment, so it often refers to stomach cancer and colorectal cancer. Now, we report a case of a patient with advanced DA who achieved complete remission (CR) after undergoing chemoradiotherapy combined with targeted therapy. The patient was pathologically diagnosed with DA after radical surgery in October 2020, and he failed to undergo adjuvant chemotherapy on time due to the COVID-19 outbreak. The patient found multiple lymph node liver and abdominal metastases 6 months after the operation. Considering the progression of the disease, XELOX regimen (oxaliplatin + capecitabine) chemotherapy was given for 1 cycle. After 1 cycle of treatment, the tumor markers remained elevated; the carcinoembryonic antigen (CEA) was 5.03 ng/ml (0–5 ng/ml), and the carbohydrate antigen 19-9 (CA19-9) was 747.30 U/ml (0–37 U/ml). The patient also developed intolerable capecitabine-related treatment-related adverse events (TRAEs), namely, hand–foot syndrome. For the above reasons, capecitabine was replaced as S-1 at cycle 2, and the chemotherapy regimen became SOX (oxaliplatin + S-1); bevacizumab injection was also added to the SOX regimen, and it was further treated regularly for 7 cycles with the regimen of SOX plus bevacizumab. Liver metastases showed a continuous narrowing trend throughout the treatment period; tumor markers also showed a downward trend. Finally, the patient achieved complete remission (CR) at cycle 7. After completion of chemotherapy, radiotherapy was administered to the resistant metastatic lymph nodes present in the patient’s abdominal cavity for a total of 10 times. However, the patient developed severe bone marrow suppression and obstructive jaundice during the course of radiotherapy and finally failed to complete the radiotherapy plan. Currently, the patient continued maintenance therapy with bevacizumab and S-1 and showed no recurrence or metastasis after review. In this case of advanced DA, we referred to both CRC and gastric cancer in the treatment regimen of the patient. At the same time, targeted drugs and radiotherapy were also added to the basis of chemotherapy, which has no clear consensus recommendation or case for reference in the treatment of advanced DA. Thankfully, the patient’s disease was controlled and remained stable after treatment with this regimen. Therefore, for patients with advanced DA who lack standardized treatment regimens and guidelines, the combination of chemotherapy with targeted therapy and radiotherapy may be one of the effective treatment modalities.

Dynamics of Endocytosis and Degradation of Antibody-Drug Conjugate T-DM1 in HER2 Positive Cancer Cells

Purpose

T-DM1 is an antibody–drug conjugate (ADC) consisting of trastuzumab and DM1 linked together. T-DM1 binds to human epidermal growth factor receptor-2 (HER2) in tumors and then triggers the endocytosis of T-DM1 and release of payload. Therefore, endocytosis efficacy is considered as a critical step for the initiation of T-DM1 therapy; however, the endocytosis mechanism of T-DM1 remains poorly understood. Meanwhile, HER2 is regarded as an internalization-resistant receptor, which hinders the endocytosis and effectiveness of T-DM1. The present study is to explore the T-DM1 endocytosis pathway, which may provide insights into the internalization mechanism of ADCs and help to improve efficacy.

Methods

Confocal microscopy and flow cytometry were used to analyse T-DM1 intracellular trafficking and endocytosis efficiency, while Western blot assay was performed to detect T-DM1 degradation.

Results

We found that intracellular T-DM1 was increased to 50% within 12 h. T-DM1 was colocalized with cholera toxin B (CTxB), a lipid raft marker, within 2 h and then degraded in lysosome. Upon overexpression of caveolin-1 (CAV-1) and utilization of caveolae/lipid-raft disruptors, we found that temporal CAV-1 upregulation significantly facilitated T-DM1 endocytosis and degradation, whereas nystatin and lovastatin disrupted caveolae/lipid-raft structure and inhibited T-DM1 degradation. We demonstrate that T-DM1 internalizes through the lipid raft-mediated endocytosis in a CAV-1 dependent manner, rather than through the clathrin-mediated endocytosis in HER2-positive cancer cells.

Conclusion

Our findings suggest that modulation of the caveolae/lipid-raft mediated endocytosis may be a possible option for improving the clinical therapeutic effect of T-DM1 because it plays a key role in regulating T-DM1 internalization.