Pyrotinib treatment on HER2-positive gastric cancer cells promotes the released exosomes to enhance endothelial cell progression, which can be counteracted by apatinib

HDACs/mTOR inhibitor synergizes with pyrotinib in HER2-positive pancreatic cancer through degradation of mutant P53

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), as a highly lethal malignancy with high mortality, lacks of effective treatment. Canonical therapeutic targets in PDAC demand further verification among which HER2 receptor tyrosine kinase inhibitor pyrotinib as treatment targets has not be decided.

METHODS

Anti-PDAC efficacy of pyrotinib was evaluated both in vitro and in vivo using both cell lines and patient-derived xenografts. By screening a large-scale library of 1453 compounds, we identified HDACs/mTOR inhibitor 1 as a promising candidate to synergize with pyrotinib. The combination therapy was evaluated in vitro and in vivo in multiple cell lines and animal models. Furthermore, RNA-seq analysis was performed to reveal the latent molecular mechanism of combination therapy.

RESULTS

In our study, pyrotinib monotherapy was found to be inefficient to anti-PDAC which exhibited limited anti-proliferation effect in vitro and in vivo. Through therapy combined with HDACs/mTOR inhibitor 1, pyrotinib triggered intense apoptosis in PDAC both in cell lines and animal models. Mechanistic analyses revealed that mutant P53 degradation mediated by HDAC inhibition synergized with HER2 and mTOR inhibition.

CONCLUSIONS

In conclusion, identification of HDACs/mTOR inhibitor as a synergistic inhibitor, provides a potent therapeutic strategy that targets HER2-positive pancreatic cancer.

The reversal of anti-HER2 resistance in advanced HER2-positive breast cancer using apatinib: two cases reports and literature review

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-targeted treatment has yielded a notable clinical benefit in patients with HER2-positive breast cancer. However, nearly 50% of patients still suffer disease progression due to resistance to HER2-targeted therapy. After the failure of macromolecular monoclonal antibodies (mAbs) therapy, we can choose small molecule tyrosine kinase inhibitors (TKIs) to reverse HER2 resistance. When small molecule TKIs resistance, we can use mAb combined with small molecule TKI, or antibody-drug conjugates (ADCs) to reverse HER2 resistance. However, then due to the availability and price of ADCs, patients may not use them. Consequently, new therapeutic approaches are required to overcome HER2-targeted therapy resistance. Vascular endothelial growth factor and its receptors (VEGF/VEGFRs) promote tumor angiogenesis. They can also activate downstream signaling pathways to promote tumorigenesis. VEGFR is a key regulator of the tyrosine kinase signaling pathway and may be a potential target in HER2-positive breast cancer. Apatinib is a small molecule TKI that specifically binds to VEGFR2 and thus exerts an antitumor effect. Although there is no definite indication for apatinib in breast cancer, it has a good benefit in advanced gastric cancer.

CASE DESCRIPTION

The two patients we reported were both HER2-positive breast cancer who we followed for more than 10 years. After the failure of multi-line anti-HER2 treatment, apatinib combined with anti-HER2 treatment had PFS of 8.4 months and 10.6 months, respectively. One patient had grade 2 hand-foot syndrome. The other had grade 2 leukopenia and grade 2 thrombocytopenia, both of them improved after control. And the best response of them were PR and SD, respectively.

CONCLUSIONS

Our cases demonstrate that, in HER2-positive breast cancer patients with HER2-targeted resistance, apatinib may be able to reverse HER2 resistance. These two cases suggest an alternative method for clinical HER2-targeted treatment of drug-resistant breast cancer patients and provide new insights for future research.

Efficacy and safety of neoadjuvant pyrotinib plus docetaxel/liposomal doxorubicin/cyclophosphamide for HER2-positive breast cancer

OBJECTIVE

Pyrotinib is a novel EGFR/HER2 dual tyrosine kinase inhibitor developed in China, while its role in neoadjuvant therapy of HER2-positive (HER2⁺) breast cancer lacks evidence. The current study aimed to explore the efficacy and safety of neoadjuvant pyrotinib plus docetaxel/liposomal doxorubicin/cyclophosphamide (TAC) for HER2⁺ breast cancer.

METHODS

A total of 27 HER2⁺ breast cancer patients received neoadjuvant pyrotinib plus TAC for 6 cycles, then surgery was performed. The clinical and pathological responses, and adverse events were evaluated.

RESULTS

Complete response rate, objective response rate, and disease control rate were 0.0%, 44.4% and 100.0% after 2 treatment cycles; 0.0%, 37.0%, and 100.0% after 4 treatment cycles; 37.0%, 37.0%, and 96.3% after 6 treatment cycles; as well as 37.0%, 44.4%, and 100.0% based on the best clinical response. Regarding pathological response, there were 1 (2.7%), 3 (11.1%), 8 (29.6%), 5 (18.5%), and 10 (37.0%) patients realizing Miller-Payne grade (G) 1, G2, G3, G4, and G5, respectively; besides, 10 (37.0%) patients achieved total pathological complete response (pCR), 10 (37.0%) patients realized pCR in breast, and 23 (85.2%) patients achieved pCR in lymph node. Additionally, adverse events included diarrhea (81.5%), dental ulcer (7.4%), and hand-foot syndrome (3.7%); meanwhile, grade 3-4 adverse event consisted of only diarrhea (11.1%).

CONCLUSION

Neoadjuvant pyrotinib plus TAC treatment is efficient and safe in HER2⁺ breast cancer patients, while further validation is needed.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Case Report: Durable Clinical Response to Third-Line Pyrotinib After Resistance to Trastuzumab in a Gastric Cancer Patient

Background

Trastuzumab plus chemotherapy remains the standard first-line treatment strategy for HER2-positive gastric cancer (GC). Trastuzumab resistance, on the other hand, remains a significant issue. There are a few effective anti-HER2 agents for patients who develop resistance to trastuzumab.

Case Presentation

A 49-year-old female was diagnosed with stage IV GC with liver and lung metastasis in July 2017. She underwent gastrostomy, and the immunohistochemistry (IHC) result of postoperative tissue demonstrated HER2 (3+). She received first-line treatment of trastuzumab (440 mg), oxaliplatin (200 mg), and S-1 (40 mg). After treatment for 6 months, the patient achieved complete response (CR) with PFS up to 21 months. After progression, she subsequently received trastuzumab (440 mg) plus oxaliplatin (200 mg) as second-line treatment. However, the patient developed resistance to trastuzumab after 12 months of treatment. She started to receive third-line treatment of irinotecan (200 mg d1) and capecitabine (60 mg bid) plus pyrotinib (400 mg/day). After 2 months of treatment, the tumor is evaluated as partial response with PFS of 12 months.

Conclusions

We presented a patient with HER2-positive GC who benefited from the pyrotinib-based treatment after two lines of trastuzumab-based therapies failed. Further research is required to validate such conclusions.

NDUFC1 Is Upregulated in Gastric Cancer and Regulates Cell Proliferation, Apoptosis, Cycle and Migration

Gastric cancer is one of the most common primary tumors of the digestive system. NADH: ubiquinone oxidoreductase subunit C1 (NDUFC1), which is an accessory subunit of the NADH dehydrogenase (complex I), is responsible for the transportation of electrons from NADH to the respiratory chain essential for the oxidative phosphorylation. However, little is known about the roles of NDUFC1 in carcinogenesis. In this study, NDUFC1 protein level in NSCLC tissues was tested by immunohistochemistry (IHC) staining. NDUFC1 mRNA level in gastric cancer cell lines was determined by qRT-PCR. MGC-803 and SGC-7901 cells were transfected with shNDUFC1 lentivirus designed to silence NDUFC1. MTT assay, CCK8 assay, wound healing assay and transwell migration assay were conducted. Cell cycle and apoptosis were detected by flow cytometry. In vivo experiments were performed using nude mice. The results indicated that overexpressed NDUFC1 in gastric cancer was related to more serious tumor infiltrates, a higher risk of lymphatic metastasis, a higher proportion of positive lymph nodes, and a more advanced tumor stage. Compared with shCtrl groups, MGC-803 and SGC-7901 of shNDUFC1 groups had lower abilities of proliferation and migration, higher levels of apoptosis. NDUFC1 knockdown also inhibited SGC-7901 cell growth in vivo and suppressed Ki67 expression in xenograft tumors. More importantly, we found that NDUFC1 downregulation made the levels of P-Akt, P-mTOR, CCND1, CDK6, PIK3CA, Bcl-2, Survivin, and XIAP decreased, and that PI3K/AKT signaling pathway agonist SC79 rescued the inhibitory effects on cell proliferation and migration, reversed the promoted effects on cell apoptosis caused by NDUFC1 knockdown. More importantly, compared with NDUFC1 knockdown group, the expression of P-Akt, Bcl-2, Survivin, and XIAP was raised in shNDUFC1 + SC79 group. Thus, our suspicion was that NDUFC1 exacerbates NSCLC progression via PI3K/Akt pathway. Taken together, our study indicated that targeting NDUFC1 could open innovative perspectives for new multi-targeting approaches in the treatment of gastric cancer.

A Review of HER4 (ErbB4) Kinase, Its Impact on Cancer, and Its Inhibitors

HER4 is a receptor tyrosine kinase that is required for the evolution of normal body systems such as cardiovascular, nervous, and endocrine systems, especially the mammary glands. It is activated through ligand binding and activates MAPKs and PI3K/AKT pathways. HER4 is commonly expressed in many human tissues, both adult and fetal. It is important to understand the role of HER4 in the treatment of many disorders. Many studies were also conducted on the role of HER4 in tumors and its tumor suppressor function. Mostly, overexpression of HER4 kinase results in cancer development. In the present article, we reviewed the structure, location, ligands, physiological functions of HER4, and its relationship to different cancer types. HER4 inhibitors reported mainly from 2016 to the present were reviewed as well.

Expression, clinical significance and correlation of RUNX3 and HER2 in colorectal cancer

Background

The incidence of colorectal cancer is high and on the rise. The genetic and protein expressions of RUNT-associated transcription factor 3 (RUNX3) and human epidermal growth factor receptor 2 (HER2) in colorectal cancer (CRC) and adjacent normal tissues were detected to preliminarily explore their correlation and clinical significance.

Methods

CRC specimens excised during general surgery were selected for localization and quantitative analysis of protein and gene expression by SP (Streptavidin-peroxidase conjugated method) immunohistochemical staining, reverse transcription-polymerase chain reaction (RT-qPCR) and western blot. Combined with the patients' data, the relationship between the expression of the two genes and tumor characteristics was analyzed. Log-rank test was used to analyze the correlation between the two proteins and survival prognosis of CRC patients. The expression of RUNX3 in RKO and HCT-116 was knocked down, and the relative expression of HER2 in the two cell lines was detected.

Results

Immunohistochemical, RT-qPCR and Western blot results showed that the positive expression rate of RUNX3 in CRC was lower than in the normal group, and HER2 in CRC was higher than in the normal group. The positive expression of the two proteins correlated with the pT and pN stages of CRC. A significant negative correlation between the expression of the two genes in CRC. Follow-up results showed that the number of Runx3-positive patients was higher than negative ones, while HER2 positive were fewer than negative ones. In vitro experiments showed that RUNX3 protein and gene expression decreased, HER2 protein and gene expression increased in RUNX3 knockdown RKO and HCT-116 cells, respectively (P<0.05).

Conclusions

The expression of RUNX3 and HER2 in CRC is related to the occurrence and development of CRC, and the two genes have a negative regulating effect.

CHSY1 is upregulated and acts as tumor promotor in gastric cancer through regulating cell proliferation, apoptosis, and migration

Gastric cancer is one of the most frequently diagnosed malignant tumors, with rapid progression and poor prognosis. The role of chondroitin sulfate synthase 1 (CHSY1) in the development and progression of gastric cancer was explored and clarified in this study. The immunohistochemistry analysis of clinical tissue samples as well as data mining of public database showed that CHSY1 was significantly upregulated in gastric cancer and associated with more advanced tumor stage and poorer prognosis. In vitro loss-of-function experiments demonstrated the inhibited cell proliferation, colony formation, cell migration, as well as the promoted cell apoptosis by CHSY1 knockdown. Moreover, recovery of CHSY1 expression could attenuate the regulatory effects induced by CHSY1 knockdown. Correspondingly, gastric cancer cells with CHSY1 knockdown showed reduced tumorigenicity and slower tumor growth in vivo. In conclusion, this study identified CHSY1 as a tumor promotor in gastric cancer, which may be utilized as a novel indicator of patients' prognosis and therapeutic target for developing more effective drug for GC treatment.

Population pharmacokinetic modeling of pyrotinib in patients with HER2-positive advanced or metastatic breast cancer

OBJECTIVE

Pyrotinib, a new oral irreversible pan-ErbB tyrosine kinase inhibitor (TKI), has been approved in China for the treatment of HER2-positive advanced or metastatic breast cancer. This study aimed to conduct a population pharmacokinetics (PK) analysis of pyrotinib and to evaluate the impact of patient characteristics on pyrotinib's PK.

METHOD

A total of 1152 samples, provided by 59 adult female patients from two phase I clinical trials, were analyzed by nonlinear mixed-effects modeling. Monte Carlo simulation was conducted to assess impact of covariates on the exposure to pyrotinib.

RESULTS

The PK of pyrotinib was adequately described by a one-compartment model with first-order absorption and elimination. Patient's age and total protein levels could affect pyrotinib's apparent volume of distribution, and concomitant use of montmorillonite could decrease the bioavailability of pyrotinib by 50.3%. No PK interactions were observed between capecitabine and pyrotinib.

CONCLUSION

In this study, a population PK model of pyrotinib was developed to determine the influence of patient characteristics on the PK of pyrotinib. While patient age and total protein levels can significantly affect the apparent distribution volume of pyrotinib, the magnitude of the impact was limited, thus no dosage adjustment was recommended. Furthermore, concomitant use of montmorillonite for diarrhea needs to be taken with precaution.

Radiosensitization of HER2-positive esophageal cancer cells by pyrotinib

Radiation therapy is a widely used treatment for esophageal cancer. However, radiation resistance might result in a poor prognosis. Overexpression of HER2 has been related to adaptive radiation resistance. Pyrotinib is a HER2 inhibitor that shows an anti-tumor effect in breast cancer. The present study aims to explore the influence of pyrotinib combined with radiotherapy on HER2-positive esophageal cancer cells and explore the underlying mechanism. We screened two cell lines (TE-1 and KYSE30) that highly express HER2 from several human esophageal cancer cell lines. Cells were treated with pyrotinib or/and radiation. Cell proliferation, cell cycle distribution, and cell migration were measured. The protein levels involved in cell cycle and DNA repair were measured by Western blot. Results showed that pyrotinib inhibited HER2 activation and exerted an anti-proliferative effect in TE-1 and KYSE30 cells. Furthermore, it enhanced the anti-proliferative effect of radiation in these two cell lines. These effects might be via inhibiting HER2 phosphorylation, inducing G0/G1 arrest, and reducing EMT and DNA repair. Our results indicated that pyrotinib sensitivitied HER2 positive esophageal cancer cells to radiation treatment through various mechanisms. These findings may provide a new therapeutic strategy for treating HER2 positive esophageal cancer.

Gastric Cancer Harboring an ERBB3 Mutation Treated with a Pyrotinib-Irinotecan Combo: A Case Study

Gastric cancer is common, especially in East Asian countries, and is associated with high recurrence and mortality rates. Currently, there is no standard third-line treatment for metastatic gastric cancer. In this report, we present the case of a 69-year-old man with advanced gastric cancer, whose tumor was negative for human epidermal growth factor receptor 2 (HER2) according to immunohistochemical analysis. Next-generation sequencing performed on paraffin sections of the postoperative tumor samples indicated the presence of the ERBB3 V104L mutation. The patient received irinotecan plus pyrotinib as a third-line therapy and achieved a progression-free survival of 7.6 months with a high quality of life. Therefore, the combined administration of irinotecan and pyrotinib may improve the clinical condition of patients with gastric cancer harboring an ERBB3 mutation. Moreover, ERBB3 could be a potential therapeutic target for gastric cancer.

Apatinib exhibits synergistic effect with pyrotinib and reverses acquired pyrotinib resistance in HER2-positive gastric cancer via stem cell factor/c-kit signaling and its downstream pathways

BACKGROUND

Recently, progress has been made in the development of targeted therapies for human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). However, drug resistance has severely limited the efficacy of anti-HER2 therapies. Pyrotinib is a novel pan-HER inhibitor. Although it is effective in HER2-positive GC treatment, its efficacy in combination with apatinib and associated resistance mechanisms in HER2-positive GC remains unclear.

METHODS

In this study, the combination effects of pyrotinib and apatinib were examined in two pyrotinib-sensitive GC cells and xenografts. The RNA sequencing was used to determine the underlying mechanisms of acquired pyrotinib resistance. The role of imatinib and apatinib in reversing pyrotinib resistance was tested in pyrotinib-resistant cells and xenografts.

RESULTS

Here, we reported that a combination of pyrotinib and apatinib exhibits synergistic effect in HER2-positive NCI-N87 xenografts, and showed enhanced antitumor efficacy in HER2-positive GC, both in vitro and in vivo. Moreover, up-regulation of the stem cell factor (SCF) levels, and the PI3K/AKT and MAPK pathways was associated with acquired pyrotinib resistance in HER2-positive GC. Mechanistically, we demonstrated that the activation of the SCF/c-kit signaling and its downstream PI3K/AKT and MAPK pathways mediated pyrotinib resistance by promoting cell survival and proliferation. Imatinib and apatinib augmented the sensitivity of pyrotinib-resistant cells and xenografts to pyrotinib, by blocking SCF/c-kit signaling.

CONCLUSION

These results highlight the effectiveness of pyrotinib combined with apatinib in HER2-positive GC and acquired pyrotinib resistance, thus providing a theoretical basis for new treatment methods.