A novel dual EGFR/HER2 inhibitor KU004 induces cell cycle arrest and apoptosis in HER2-overexpressing cancer cells

Nanotechnology-Based Diagnostic and Therapeutic Strategies for Neuroblastoma

Neuroblastoma (NB), as the most common extracranial solid tumor in childhood, is one of the critical culprits affecting children's health. Given the heterogeneity and invisibility of NB tumors, the existing diagnostic and therapeutic approaches are inadequate and ineffective in early screening and prognostic improvement. With the rapid innovation and development of nanotechnology, nanomedicines have attracted widespread attention in the field of oncology research for their excellent physiological and chemical properties. In this review, we first explored the current common obstacles in the diagnosis and treatment of NB. Then we comprehensively summarized the advancements in nanotechnology-based multimodal synergistic diagnosis and treatment of NB and elucidate the underlying mechanisms. In addition, a discussion of the pending challenges in biocompatibility and toxicity of nanomedicine was conducted. Finally, we described the development and application status of nanomaterials against some of the recognized targets in the field of NB research, and pointed out prospects for nanomedicine-based precision diagnosis and therapy of NB.

EGFR inhibitors regulate Ca2+ concentration and apoptosis after PM2.5 exposure based on a lung-mimic microfluidic system

Air pollution has side effects on human health. Epidemiology studies indicate a positive association between ambient fine particle (PM_2.5, or particles less than 2.5 μm in diameter) concentration and lung cancer. However, how fine particles affect lung cancer at the molecular level and related therapeutic methods to address these diseases are unclear. Here, the multi-omics analysis (DNA methylation and transcriptomic) was used to detect human bronchial epithelial cells (HBE), that were exposed to PM_2.5 using a quantified, small, portable, and organ-level air-liquid interface microfluidic system that mimics lung functions. The results indicate that 36,838 differentially methylated genes were detected. Of these 33,796 genes were hypomethylated (beta < 0), and 2862 genes were hypermethylated (beta > 0). RNA-Seq analysis demonstrated that 19,489 genes were upregulated (log₂FC > 0), and 16,659 were downregulated. Furthermore, the calcium and apoptosis pathways were activated according to multi-omics analysis. The change in EGFR gene expression after PM_2.5 exposure was the result of alterations of the cellular DNA methylome in the promoter. Inhibition or down-regulation of EGFR could result in the regulation of the downstream intracellular Ca²⁺ concentration and apoptosis via the EGFR/PLCγ and EGFR/STAT/Bcl-XL pathways after PM_2.5 exposure. EGFR inhibitors decrease the Ca²⁺ concentration of cells, thereby strengthening the effects of fine particles on apoptosis. In short, the Ca²⁺ concentration and the apoptosis of cells can be regulated via EGFR related pathway after PM_2.5 exposure. The EGFR may be a potentially promising therapeutic target for the treatment of air pollution-induced lung cancer through regulation of the intracellular Ca²⁺ concentration and apoptosis.

Knockdown of ROS proto-oncogene 1 inhibits migration and invasion in gastric cancer cells by targeting the PI3K/Akt signaling pathway

Objectives

Gastric cancer ranks the fourth most common cancer and the third leading cause of cancer mortality in the world. ROS proto-oncogene 1 (ROS1) is an oncogene and ROS1 rearrangement has been reported in many cancers. Our study aimed to investigate the potential function and the precise mechanisms of ROS1 in gastric cancer.

Methods

In our study, the analysis of ROS1 expression and clinical pathologic factors of gastric cancer in gastric cancer using TCGA database demonstrated that ROS1 expression was elevated in gastric cancer and related to T, N, M and TNM staging. High expression of ROS1 predicted poor survival in patients with gastric cancer. Then, we measured ROS1 expression in four human gastric cancer cell lines and knocked down ROS1 expression in BGC-823 and SGC-7901 cells by specific shRNA transfection via Lipofectamine 2000. The effect of ROS1 knockdown on cell proliferation, cell cycle distribution, cell apoptosis and metastasis in vitro was evaluated by MTT, colony formation, flow cytometric analysis, wound healing and Transwell invasion assays. The levels of apoptosis-related proteins, EMT markers and the PI3K/Akt signaling pathway members were measured by Western blotting.

Results

We demonstrated that shROS1 transfection markedly downregulated ROS1 expression in BGC-823 and SGC-7901 cells. Knockdown of ROS1 inhibited cell survival, clonogenic growth, migration, invasion and epithelial–mesenchymal transition (EMT), as well as induced cell cycle arrest and apoptosis in gastric cancer cells. Furthermore, ROS1 knockdown inhibited the phosphorylation of PI3K and Akt.

Conclusion

Collectively, our data suggest that ROS1 may serve as a promising therapeutic target in gastric cancer treatment.

Novel treatment strategies for patients with HER2-positive breast cancer who do not benefit from current targeted therapy drugs

Human epidermal growth factor receptor-2 positive breast cancer (HER2+ BC) is characterized by a high rate of metastasis and drug resistance. The advent of targeted therapy drugs greatly improves the prognosis of HER2+ BC patients. However, drug resistance or severe side effects have limited the application of targeted therapy drugs. To achieve more effective treatment, considerable research has concentrated on strategies to overcome drug resistance. Abemaciclib (CDK4/6 inhibitor), a new antibody-drug conjugate (ADC), src homology 2 (SH2) containing tyrosine phosphatase-1 (SHP-1) and fatty acid synthase (FASN) have been demonstrated to improve drug resistance. In addition, using an effective vector to accurately deliver drugs to tumors has shown good application prospects. Many studies have also found that natural anti-cancer substances produced effective results during in vitro and in vivo anti-HER2+ BC research. This review aimed to summarize the current status of potential clinical drugs that may benefit HER2+ BC patients in the future.

Restoration of Arpin suppresses aggressive phenotype of breast cancer cells

Arpin, a negative regulator of the actin-related protein-2/3 (Arp2/3) complex, is downregulated and predicts poor prognosis in breast cancer patients. However, its biological relevance in breast cancer is still unclear. This study was conducted to investigate the roles of Arpin in breast cancer growth and invasion. We overexpressed Arpin expression in MCF-7 and MDA-MB-231 breast cancer cells and examined the effects of restoration of Arpin on cell proliferation, colony formation, cell cycle distribution, invasion in vitro and tumorigenesis in vivo. The related molecular mechanism(s) was determined. It was found that ectopic expression of Arpin significantly decreased cell proliferation, colony formation, and tumorigenicity. Flow cytometric analysis showed that overexpression of Arpin significantly increased the percentage of G0/G1-phase cells and decreased the percentage of S-phase cells. Moreover, restoration of Arpin impaired the invasiveness of breast cancer cells, as determined by Transwell invasion assays. Mechanistically, overexpression of Arpin inhibited the phosphorylation of Akt in breast cancer cells. Co-expression of a constitutively active form of Akt blunted the suppression of cell proliferation and invasion by Arpin. Taken together, we provide evidence that Arpin acts as a tumor suppressor in breast cancer, which is associated with inhibition of Akt signaling. Restoration of Arpin may represent a promising therapeutic strategy against breast cancer progression.

Inhibition of glycolysis by a novel EGFR/HER2 inhibitor KU004 suppresses the growth of HER2+ cancer

Upregulation of glycolysis was often observed in human HER2-overexpressing cancers. In this study, we demonstrated that KU004, a dual novel EGFR/HER2 inhibitor, disrupted cancer cell proliferation via modulation of glycolysis. KU004, inhibited the Warburg effect by suppressing hexokinase II (HK2) expression at the transcriptional and post-translational levels. Further study demonstrated that the downregulation of HKII by KU004 was mainly mediated by the PI3K/Akt signaling pathway. Furthermore, the role of HKII downregulation in KU004-mediated antitumor effect was also confirmed in our in vivo xenograft model. Collectively, these data suggest that multifaceted targeting the aberrant glucose metabolism along with the upstream HER2 may be an effective approach for clinical treatment against HER2+ cancer.

Downregulation of NPM expression by Her-2 reduces resistance of gastric cancer to oxaliplatin

Nucleophosmin (NPM) and human epidermal growth factor receptor-2 (Her-2) are abnormally expressed in various types of human malignant tumors, including gastric cancer, and have been closely associated with cancer chemoresistance. However, their interaction and roles in oxaliplatin resistance are not fully understood. Therefore, the present study aimed to elucidate the relationship between NPM and Her-2 in gastric cancer cell lines and clinical samples, and further investigated their role in the resistance of gastric cancer to oxaliplatin. Western blotting and reverse transcription-quantitative polymerase chain reaction confirmed that NPM and Her-2 expression were significantly upregulated in gastric cancer cells and clinical samples, and that their expression levels were strongly correlated. However, Her-2 expression was not affected by upregulation or downregulation of NPM expression in gastric cancer cells. Cell counting kit-8 assays demonstrated that the cell sensitivity to oxaliplatin decreased simultaneously with an increase in NPM expression. Furthermore, inhibition of Her-2 expression using trastuzumab significantly increased the sensitivity of the cells to oxaliplatin, which occurred simultaneously with the downregulation of NPM. These results indicated that inhibition of NPM, as a Her-2 downstream signal, may be a novel strategy to overcome oxaliplatin-resistant gastric cancer, and that trastuzumab and oxaliplatin may exhibit a synergistic antitumor effect in Her-2-positive gastric cancer cells.

Design and Synthesis of Near-Infrared Peptide for in Vivo Molecular Imaging of HER2

We report the development, characterization, and validation of a peptide specific for the extracellular domain of HER2. This probe chemistry was developed for molecular imaging by using a structural model to select an optimal combination of amino acids that maximize the likelihood for unique hydrophobic and hydrophilic interactions with HER2 domain 3. The sequence KSPNPRF was identified and conjugated with either FITC or Cy5.5 via a GGGSK linker using Fmoc-mediated solid-phase synthesis to demonstrate flexibility for this chemical structure to be labeled with different fluorophores. A scrambled sequence was developed for control by altering the conformationally rigid spacer and moving both hydrophobic and hydrophilic amino acids on the C-terminus. We validated peptide specificity for HER2 in knockdown and competition experiments using human colorectal cancer cells in vitro, and measured a binding affinity of kd = 21 nM and time constant of k = 0.14 min(-1) (7.14 min). We used this peptide with either topical or intravenous administration in a preclinical model of colorectal cancer to demonstrate specific uptake in spontaneous adenomas and to show feasibility for real time in vivo imaging with near-infrared fluorescence. We used this peptide in immunofluorescence studies of human proximal colon specimens to evaluate specificity for sessile serrated and sporadic adenomas. Improved visualization can be used endoscopically to guide tissue biopsy and detect premalignant lesions that would otherwise be missed. Our peptide design for specificity to HER2 is promising for clinical translation in molecular imaging methods for early cancer detection.