Gefitinib, an epidermal growth factor receptor (EGFR)‑specific drug, is effective for ~1 year, after which resistance is inevitable. Calpain 2 (CAPN2) is known to serve a role in the drug response and resistance in certain cancer therapies. However, the full function of CAPN2, particularly in non‑small cell lung cancer, has not yet been elucidated. In the present study, CAPN2 expression in gefitinib‑resistant lung adenocarcinoma cells was investigated. CAPN2 function in these cells was further evaluated using gene knockdown both in vitro and in vivo. The results demonstrated that CAPN2 was strongly associated with gefitinib‑resistance, and CAPN2 mRNA and protein expression levels were significantly increased in gefitinib‑resistant cell lines. Furthermore, CAPN2 knockdown inhibited gefitinib‑resistant cell proliferation in vitro and in vivo. CAPN2 conferred gefitinib‑resistance by inhibiting cell apoptosis and arresting the cell cycle. CAPN2 knockdown also induced caspase activation and mitochondrial dysfunction, and its function in gefitinib resistance appeared to be largely mediated by EGFR/protein kinase B/survivin signaling pathway activation. These results suggest that CAPN2 is responsible for EGFR‑tyrosine kinase inhibitor resistance, and CAPN2 inhibition may be used to provide therapeutic benefits in the treatment of gefitinib resistance.

Both epidermal growth factor receptor (EGFR) and the Yes-associated protein (YAP) signaling pathway are implicated in cell proliferation and differentiation. In this study, we explored whether the formation of proliferative vitreoretinopathy (PVR) depends on the interaction of the EGFR receptor and YAP pathway.

Aminoflavone (AF) acts as a ligand of the aryl hydrocarbon receptor (AhR). Expression of estrogen receptor α (ERα) and AhR-mediated transcriptional induction of CYP1A1 can sensitize breast cancer cells to AF. The objective of this study was to investigate the combined antitumor effect of AF and the histone deacetylase inhibitor vorinostat for treating mesenchymal-like triple-negative breast cancer (TNBC) as well as the underlying mechanisms of such treatment.

Pancreatic cancer (PC) is the most lethal type of gastrointestinal cancer, and early detection and monitoring is an urgent problem. Circulating tumor cells (CTCs) are emerging as a non-invasive biomarker for tumor detection. However, the low sensitivity is a main problem in the traditional CellSearch System for detecting CTCs, especially in patients with PC. In this study, we used negative enrichment (NE), immunofluorescence and in situ hybridization (FISH) of chromosome 8 (NE-iFISH) to capture and identify CTCs in PC patients. We showed that the NE-iFISH system exhibited a dramatically high detection rate of CTCs in PC patients (90%). The diagnostic rate of PC reached 97.5% when combining CTCs ≥ 2 and carbohydrate antigen 19-9 (CA19-9) > 37 µmol/L. The 1-year survival in the group of CTCs < 3 was significantly higher than that of CTCs ≥ 3 (p = 0.043). In addition, we analyzed the role of chromosomal instability in CTCs detection. The group of triploid (three hybridization signals of chromosome 8) CTCs ≥ 3 showed a shorter 1-year survival (p = 0.0279) and overall survival (p = 0.0188) than the group with triploid CTCs < 3. Importantly, the triploid CTC number but not the overall CTC counts could be a predictor of chemo-sensitivity. Moreover, circulating tumor microembolus (CTMs) were found in stage IV patients, and were positively related to the poor response to chemotherapy. In conclusion, the NE-iFISH system significantly improved the positive detection rate of CTCs and triploid CTC could be used to predict prognosis or the response to the chemotherapy of PC patients. CTM is a potential indicator of the chemotherapeutic effect in advanced PC patients.

This study compared the clinical efficacy of first-, second-, and third-generation tyrosine kinase inhibitors (TKIs) in previously untreated non-small cell lung cancer (NSCLC) patients harboring uncommon epidermal growth factor receptor (EGFR) exon 19delins variants.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, including gefitinib, are first-line drugs against advanced non-small cell lung cancer with activating EGFR mutations. However, the development of resistance to such drugs is a major clinical challenge.

Although trastuzumab is the standard of care for patients with human epidermal growth factor receptor 2 (HER2)- positive early breast cancer (EBC), drug resistance and disease relapse occur. Therefore, we performed a meta-analysis to assess the efficacy and safety of trastuzumab-containing dual anti-HER2 therapy compared to trastuzumab alone.

Tyrosine kinase inhibitors (TKIs), such as gefitinib, are widely used as standard treatments for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations. However, the subsequent inevitable drug resistance has become a major challenge in clinical treatment. The aim of this study was to investigate the role of tissue-type plasminogen activator (PLAT) in gefitinib resistance in NSCLC.

The concordance rate of human epidermal growth factor receptor 2 (HER2) status between core needle biopsy (CNB) and subsequent excisional biopsies of the same tumor varies from 81 to 96%, which may cause inappropriate neoadjuvant therapy that impair the potential benefit from HER2 targeted therapy for patients. This study aimed to establish a nomogram to predict the HER2 status pre-operatively as an auxiliary diagnosis to CNB assessment.

Breast cancer is the most common malignancy in women. Triple-negative breast cancer (TNBC) refers to a special subtype that is deficient in the expression of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER-2). In this study, a variety of bioinformatics analysis tools were used to screen Hub genes related to the occurrence and development of triple negative breast cancer, and their biological functions were analyzed.

Myeloid-derived suppressor cells (MDSC) and M2 monocytes/macrophages are two types of suppressive myeloid antigen presenting cells that have been shown to promote tumor progression and correlate with poor prognosis in cancer patients. Tumor antigen specific monoclonal antibodies (mAb) have emerged as important agents for cancer therapy. In addition to the direct inhibition of tumor growth, the Fc portions of the therapeutic mAbs, such as the IgG1 portion of the anti-epidermal growth factor receptor (EGFR) mAb cetuximab, might interact with the Fc-gamma receptors (FcγR) on myeloid cells and modulate their suppressive activity.

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy with extremely poor therapeutic outcome due to high drug resistance, widespread metastasis and lack of effective treatment options. CCA progression and metastasis are regulated by multiple biological factors including multiple miRNAs and chemokine receptor CXCR4. The goal of this study was to test if nanotherapeutic blockade of CXCR4 by polymeric CXCR4 antagonist (PCX) combined with inhibition of hypoxia-inducible miR-210 cooperatively enhances therapeutic efficacy in CCA through reducing invasiveness, inducing cell killing, and reversing drug resistance. Methods: We first tested the activity of PCX to inhibit migration of CCA cells. We then prepared PCX/anti-miRNA nanoparticles and analyzed their miRNA delivery efficacy and anticancer activity in vitro. Finally, in vivo biodistribution assay and anticancer activity study were performed in CCA tumor-bearing mice. Results: Our results show that PCX had a broad inhibitory effect on cell migration, effectively delivered anti-miR-210, and downregulated miR-210 expression in CCA cells. Combination PCX/anti-miR-210 nanoparticles showed cytotoxic activity towards CCA cells and reduced the number of cancer stem-like cells. The nanoparticles reversed hypoxia-induced drug resistance and sensitized CCA cells to standard gemcitabine and cisplatin combination treatment. Systemic intravenous treatment with the nanoparticles in a CCA xenograft model resulted in prominent combined antitumor activity. Conclusion: Our findings support PCX-based nanoparticles as a promising delivery platform of therapeutic miRNA in combination CCA therapies.

Disassembly of nucleosomes in which genomic DNA is packaged with histone regulates gene expression. However, the mechanisms underlying nucleosome disassembly for gene expression remain elusive. We show here that epidermal growth factor receptor activation results in the binding of the RNF8 forkhead-associated domain to pyruvate kinase M2-phosphorylated histone H3-T11, leading to K48-linked polyubiquitylation of histone H3 at K4 and subsequent proteasome-dependent protein degradation. In addition, H3 polyubiquitylation induces histone dissociation from chromatin, nucleosome disassembly, and binding of RNA polymerase II to MYC and CCND1 promoter regions for transcription. RNF8-mediated histone H3 polyubiquitylation promotes tumor cell glycolysis and proliferation and brain tumorigenesis. Our findings uncover the role of RNF8-mediated histone H3 polyubiquitylation in the regulation of histone H3 stability and chromatin modification, paving the way to gene expression regulation and tumorigenesis.

Metastasis accounts for the vast majority of deaths in breast cancer, and novel and effective treatments to inhibit cancer metastasis remain urgently developed. The expression level of heat shock protein 90 (HSP90) in invasive breast cancer tissue is higher than in adjacent non-cancerous tissue. In the present study, we investigated the inhibitory effect of penisuloxazin A (PNSA), a novel C- terminal inhibitor of HSP90, on metastasis of breast cancer cells and related mechanism in vitro. We found that PNSA obviously affected adhesion, migration, and invasion of triple-negative breast cancer (TNBC) MDA-MB-231 cells and Trastuzumab-resistant JIMT-1 cells. Furthermore, PNSA was capable of reversing epithelial-mesenchymal transformation (EMT) of MDA-MB-231 cells with change of cell morphology. PNSA increases E-cadherin expression followed by decreasing amounts of N-cadherin, vimentin, and matrix metalloproteinases9 (MMP9) and proteolytic activity of matrix metalloproteinases2 (MMP2) and MMP9. Comparatively, the N-terminal inhibitor of HSP90 17-allyl-17-demethoxygeldanamycin (17-AAG) had no effect on EMT of MDA-MB-231 cells. PNSA was uncovered to reduce the stability of epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor (FGFR) proteins and thereby inhibiting their downstream signaling transductions by inhibition of HSP90. In addition, PNSA reduced the expression of programmed cell death-ligand 1 (PD-L1) to promote natural killer (NK) cells to kill breast cancer cells with a dose far less than that of cytotoxicity to NK cell itself, implying the potential of PNSA to enhance immune surveillance against metastasis in vivo. All these results indicate that PNSA is a promising anti-metastasis agent worthy of being studied in the future.

Lung cancer remains one of the most common cancer-associated mortalities worldwide, and platinum-based doublet chemotherapies are recommended as the first‑line treatment for advanced non‑small cell lung cancer (NSCLC). However, the frequent development of multidrug resistance, to cisplatin regimens in particular, is a major cause of chemotherapy failure in patients with aggressive NSCLC. Wnt/β‑catenin signaling and sex‑determining region Y box 2 (Sox2) have been implicated in the development and progression and resistance to epidermal growth factor receptor‑targeting therapy in lung cancer. The present study aimed to explore the effects of Wnt/β‑catenin and Sox2 signaling on the chemoresistance of cisplatin‑resistant lung cancer cells by assessing the effects of Sox2 on Wnt/β‑catenin signaling activity, cell migration, invasion and clonogenicity, and susceptibility to cisplatin in lung adenocarcinoma A549 cells and cisplatin-resistant A549/DDP cells. The results demonstrated that an enforced expression of Sox2 led to inhibition of Wnt/β-catenin signaling activity, potentially by upregulating glycogen synthase kinase 3 β in A549 and A549/DDP cells. An overexpression of Sox2 promoted cell migration and invasion, in addition to enhancing the clonogenic capacity in A549 cells. Notably, knockdown Sox2 using short hairpin RNA led to an enhanced susceptibility of A549 and A549/DDP cells to cisplatin, along with increased cell apoptosis. The present study thus suggests that Sox2 may be an important regulator in development of chemoresistance of lung cancer cells and may be a novel therapeutic target for treatment chemoresistant lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib have been widely used in patients with non-small-cell lung cancer. Unfortunately, the efficacy of EGFR-TKIs is limited because of natural and acquired resistance. As a novel cytoprotective mechanism for tumor cell to survive under unfavorable conditions, autophagy has been proposed to play a role in drug resistance of tumor cells. Whether autophagy can be activated by gefitinib or erlotinib and thereby impair the sensitivity of targeted therapy to lung cancer cells remains unknown. Here, we first report that gefitinib or erlotinib can induce a high level of autophagy, which was accompanied by the inhibition of the PI3K/Akt/mTOR signaling pathway. Moreover, cytotoxicity induced by gefitinib or erlotinib was greatly enhanced after autophagy inhibition by the pharmacological inhibitor chloroquine (CQ) and siRNAs targeting ATG5 and ATG7, the most important components for the formation of autophagosome. Interestingly, EGFR-TKIs can still induce cell autophagy even after EGFR expression was reduced by EGFR specific siRNAs. In conclusion, we found that autophagy can be activated by EGFR-TKIs in lung cancer cells and inhibition of autophagy augmented the growth inhibitory effect of EGFR-TKIs. Autophagy inhibition thus represents a promising approach to improve the efficacy of EGFR-TKIs in the treatment of patients with advanced non-small-cell lung cancer.

Cluster of differentiation 44 (CD44) as a transmembrane glycoprotein is found to be expressed in non‑small cell lung cancer (NSCLC), is significantly associated with NSLC progression, metastasis and drug resistance. This study aimed to explore whether CD44 inhibition improves the sensitivity of epidermal growth factor receptor (EGFR) wild‑type NSCLC cells to cisplatin and how it affects wild‑type EGFR in NSCLC cells. Small interfering RNA was used to knockdown CD44 expression in EGFR wild‑type NSCLC cell line H460. Results suggested that CD44 downregulation reduced cell growth, promoted G0/G1 cell cycle arrest and induced cell apoptosis in H460 cells and these effects were evidently enhanced when in combination with cisplatin. Deactivation of EGFR signaling pathway including EGFR phosphorylation and its downstream molecules, targets ERK, AKT1 and SRC which were also observed in CD44‑silenced H460 cells with or without EGF stimulation. Furthermore, the CD44 expression level was positively correlated with wild‑type EGFR level in human lung adenocarcinoma tissues and CD44 inhibition significantly accelerated the degradation of EGFR, indicating that enhanced sensitivity of H460 cells to cisplatin by downregulation of CD44 might be due to EGFR degradation. This study demonstrated that suppression of CD44 deactivated EGFR signals in NSCLC cells with wild‑type EGFR, thereby contributing to the inhibition of cell proliferation and the reinforcement of cisplatin sensitivity. It is suggested that downregulation of CD44 could be a novel potential therapeutic strategy for the treatment of EGFR wild‑type NSCLC.

Leucine-rich α-2-glycoprotein-1 (LRG1) is involved in several pathophysiological processes, including angiogenesis, cutaneous wound repair and cancer metastasis. In this study, we investigated the potential role and mechanism of LRG1 in corneal re-epithelialisation and nerve regeneration in streptozotocin-induced diabetic mice. We found decreased levels of LRG1 in the corneal epithelium after wounding in diabetic mice compared to normal controls. Hyperglycaemia downregulated the LRG1 expression in the corneal epithelium in vivo, as well as in vitro in a cultured mouse corneal epithelial stem/progenitor cell line (TKE2 cells) exposed to high glucose (HG; 30 mM) in the culture medium. Exogenous application of LRG1 accelerated corneal re-epithelialisation and nerve regeneration in normal mice and diabetic mice. LRG1 also overcame the suppression of wound healing in TKE2 cells by HG conditions, and it activated repair-related signalling by JAK2/STAT3, AKT, epidermal growth factor receptor (EGFR) and transforming growth factor (TGF)-β3. We also found that LRG1 treatment overcame the hyperglycaemia-suppressed expression of matrix metalloproteinase 3 (MMP3) and metalloproteinase 13 (MMP13) in the regenerated corneal epithelium. The promoted effects of LRG1 on corneal re-epithelialisation and nerve regeneration were blocked by inhibitors of MMP3 and MMP13. Subconjunctival injection of 0.5 μg MMP inhibitors did not cause any obvious toxic damage in corneal epithelial cells. Immunoprecipitation and proximity ligation assay experiments confirmed that endogenous LRG1 coprecipitated with MMP3 and MMP13 in TKE2 cells. These results indicate that LRG1 promoted wound repair and nerve regeneration in the diabetic corneal epithelium by regulation of MMPs. Our findings reveal a new function and mechanism for LRG1 in the cornea, and they provide new insights for a better understanding of diabetic keratopathy.

Sorafenib is a highly selective multi-targeted agent and has been reported to have potent antitumor effects against various tumors, including human non-small cell lung cancer (NSCLC). In the present study, we explored the antitumor effect and associated molecular mechanisms of sorafenib against human lung cancer cell lines in vitro. We also investigated the efficacy of concurrent and sequential administration of sorafenib and gemcitabine in epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI)-sensitive and EGFR-TKI-resistant NSCLC cell lines. The PC-9 (EGFR-TKI-sensitive, EGFR-mutated) and A549 (EGFR-TKI-resistant, K-Ras-mutated) NSCLC cell lines were treated with sorafenib and gemcitabine, alone, in combination or with different schedules. Cytotoxicity was assessed by MTT assay, cell cycle distribution was analyzed by flow cytometry and alterations in signaling pathways were analyzed by western blotting. We found that sorafenib exhibited dose-dependent growth inhibition in the EGFR-TKI-sensitive and EGFR-TKI-resistant NSCLC cell lines, and the sequence gemcitabine→sorafenib exhibited the strongest synergism. Sorafenib arrested the cell cycle at G1 phase, whereas gemcitabine caused arrest at S phase. The molecular mechanism of this synergism is that the downstream signaling pathways that were initially activated by gemcitabine exposure were efficiently suppressed by the subsequent exposure to sorafenib. By contrast, the reverse of this sequential administration resulted in antagonism, which may be due to differential effects on cell cycle arrest. The results suggest that sorafenib as a single agent exhibits anti-proliferative effects in vitro in NSCLC cell lines with EGFR and K-Ras mutations and that the sequential administration of gemcitabine followed by sorafenib is superior to sorafenib followed by gemcitabine and concurrent administration.

Background: The significance of uncommon epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC) and brain metastasis (BM) remains unclear. Cerebrospinal fluid (CSF) liquid biopsy is a novel tool for assessing EGFR mutations in BM. This study aimed to evaluate the EGFR mutations in patients with NSCLC and newly diagnosed BM and to examine the effect of EGFR tyrosine kinase inhibitors (TKI) on BM harboring CSF-tested uncommon EGFR mutations. Methods: This was a prospective study of 21 patients with NSCLC and BM diagnosed between 04/2018 and 01/2019. CSF was obtained to detect the BM EGFR mutations by next-generation sequencing. BM characteristics at magnetic resonance imaging (MRI) and EGFR-TKI response were examined. Results: Of 21 patients with NSCLC, 10 (47.6%) had leptomeningeal metastasis (LM), while 11 (52.4%) had brain parenchymal metastasis (BPM); 13 (61.9%) had confirmed EGFR mutation-positive primary tumors. The uncommon mutation rate in CSF ctDNA was 33.3% (7/21). Among those with EGFR mutation-positive primary tumors, the rate of uncommon EGFR mutations in CSF was 53.8% (7/13). Uncommon EGFR mutations were more common in patients with LM than in patients with PBM (6/11, 54.5% vs. 1/10, 10%), and included G719A, L861Q, L703P, and G575R. TKI was effective for four patients with BMs harboring uncommon EGFR mutations. Conclusion: In patients with NSCLC and LM, the rate of uncommon EGFR mutation was high. The BMs with uncommon EGFR mutations seem to respond to EGFR-TKI treatment. CSF liquid biopsy could reveal the EGFR genetic profile of the BM and help guide treatment using small-molecule TKI.