BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

OBJECTIVE: To explore the association between expression of ADAM17 and cetuximad resistance in human colorectal cancer SW480 cells. METHODS: The expression of ADAM17 was detected using Western blotting in different human colorectal cancer cell lines, and the cells highly expressing ADAM17 were selected as the target cells. SW480 cells were transfected with ADAM17-siRNA 1 and ADAM17-siRNA 2 and the changes in the expression of ADAM17 protein were detected using Western blotting. SW480 cells were exposed to cetuximad for 24 h and the cell apoptosis was analyzed using flow cytometry. Transwell assay was used to examine the migration ability of SW480 cells with different expression levels of ADAM17; Western blotting was used to analyze the changes in the expressions of AKT signaling pathway-related proteins in the treated cells. RESULTS: The baseline expressions of ADAM17 were significantly higher in SW480 cells than in the other human colorectal cancer cell lines tested ( < 0.05). Both ADAM17-siRNA 1 and 2 effectively reduced the expression of ADAM17 protein in SW480 cells. Knockdown of ADAM17 with siRNA 1 significantly increased the sensitivity of SW480 cells to tocetuximad ( < 0.05), obviously inhibited the cell proliferation, migration and invasion, and significantly reduced the expressions of p-EGFR and p-AKT in the cells ( < 0.001). CONCLUSIONS ADAM17 knockdown obviously inhibits EGFR-AKT signaling pathway and increases the sensitivity of SW480 cells to tocetuximad.
ADAM17 Protein ; genetics ; metabolism ; Antineoplastic Agents, Immunological ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cetuximab ; pharmacology ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Drug Resistance, Neoplasm ; genetics ; ErbB Receptors ; metabolism ; Gene Knockdown Techniques ; Humans ; Neoplasm Invasiveness ; Oncogene Protein v-akt ; metabolism ; RNA, Small Interfering ; Signal Transduction ; Transfection ; methods

PURPOSE: Rearrangement of the proto-oncogene rearranged during transfection (RET) has been newly identified potential driver mutation in lung adenocarcinoma. Clinically available tyrosine kinase inhibitors (TKIs) target RET kinase activity, which suggests that patients with RET fusion genes may be treatable with a kinase inhibitor. Nevertheless, the mechanisms of resistance to these agents remain largely unknown. Thus, the present study aimed to determine whether epidermal growth factor (EGF) and hepatocyte growth factor (HGF) trigger RET inhibitor resistance in LC-2/ad cells with CCDC6-RET fusion genes. MATERIALS AND METHODS: The effects of EGF and HGF on the susceptibility of a CCDC6-RET lung cancer cell line to RET inhibitors (sunitinib, E7080, vandetanib, and sorafenib) were examined. RESULTS: CCDC6-RET lung cancer cells were highly sensitive to RET inhibitors. EGF activated epidermal growth factor receptor (EGFR) and triggered resistance to sunitinib, E7080, vandetanib, and sorafenib by transducing bypass survival signaling through ERK and AKT. Reversible EGFR-TKI (gefitinib) resensitized cancer cells to RET inhibitors, even in the presence of EGF. Endothelial cells, which are known to produce EGF, decreased the sensitivity of CCDC6-RET lung cancer cells to RET inhibitors, an effect that was inhibited by EGFR small interfering RNA (siRNA), anti-EGFR antibody (cetuximab), and EGFR-TKI (Iressa). HGF had relatively little effect on the sensitivity to RET inhibitors. CONCLUSION: EGF could trigger resistance to RET inhibition in CCDC6-RET lung cancer cells, and endothelial cells may confer resistance to RET inhibitors by EGF. E7080 and other RET inhibitors may provide therapeutic benefits in the treatment of RET-positive lung cancer patients.
Adenocarcinoma/drug therapy/*genetics ; Cell Line, Tumor ; Cetuximab/pharmacology ; Drug Resistance, Neoplasm/drug effects/*genetics ; Epidermal Growth Factor/metabolism/*pharmacology ; *Gene Rearrangement ; Hepatocyte Growth Factor/*pharmacology ; Humans ; Indoles/pharmacology ; Lung Neoplasms/drug therapy/*genetics ; MAP Kinase Signaling System ; *Mutation ; Niacinamide/analogs & derivatives/pharmacology ; Phenylurea Compounds/pharmacology ; Piperidines/pharmacology ; Protein Kinase Inhibitors/therapeutic use ; Proto-Oncogene Proteins c-ret/*antagonists & inhibitors/genetics ; Pyrroles/pharmacology ; Quinazolines/pharmacology ; RNA, Small Interfering/pharmacology ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Signal Transduction/drug effects ; fms-Like Tyrosine Kinase 3/metabolism

The NCCN has recently released its 2017 version 1.0 guideline for colorectal cancer. There are several updates from this new version guideline which are believed to change the current clinical practice. Update one, low-dose aspirin is recommended for patients with colorectal cancer after colectomy for secondary chemoprevention. Update two, biological agents are removed from the neoadjuvant treatment regimen for resectable metastatic colorectal cancer (mCRC). This update is based on lack of evidence to support benefits of biological agents including bevacizumab and cetuximab in the neoadjuvant setting. Both technical criteria and prognostic information should be considered for decision-making. Currently biological agents may not be excluded from the neoadjuvant setting for patients with resectable but poor prognostic disease. Update three, panitumumab and cetuximab combination therapy is only recommended for left-sided tumors in the first line therapy. The location of the primary tumor can be both prognostic and predictive in response to EGFR inhibitors in metastatic colorectal cancer. Cetuximab and panitumumab confer little benefit to patients with metastatic colorectal cancer in the primary tumor originated on the right side. On the other hand, EGFR inhibitors provide significant benefit compared with bevacizumab-containing therapy or chemotherapy alone for patients with left primary tumor. Update four, PD-1 immune checkpoint inhibitors including pembrolizumab or nivolumab are recommended as treatment options in patients with metastatic deficient mismatch repair (dMMR) colorectal cancer in second- or third-line therapy. dMMR tumors contain thousands of mutations, which can encode mutant proteins with the potential to be recognized and targeted by the immune system. It has therefore been hypothesized that dMMR tumors may be sensitive to PD-1 inhibitors.
Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; therapeutic use ; Antineoplastic Agents ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Aspirin ; administration & dosage ; therapeutic use ; Bevacizumab ; therapeutic use ; Biological Products ; therapeutic use ; Brain Neoplasms ; drug therapy ; genetics ; Cetuximab ; therapeutic use ; Clinical Decision-Making ; methods ; Colorectal Neoplasms ; drug therapy ; genetics ; pathology ; prevention & control ; therapy ; Contraindications ; Humans ; Mutation ; physiology ; Neoadjuvant Therapy ; standards ; Neoplasm Metastasis ; drug therapy ; Neoplastic Syndromes, Hereditary ; drug therapy ; genetics ; Practice Guidelines as Topic ; Prognosis ; Secondary Prevention ; methods ; standards

OBJECTIVETo investigate the role of epidermal growth factor receptor (EGFR) expression level in cetuximab cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC) effect against A549 lung cancer cell line.

METHODSA549 cell line and NKTm cells were used as the target cell and the effector cell, respectively. pEGFR-EGFP plasmids were transfected into A549 cells by nucleofector method. EGFR expression levels were measured by immunohistochemistry. The ADCC activity induced by cetuximab was assessed by cell counting kit-8 assay.

RESULTSA549 cells transfected with pEGFR-EGFP plasmids expressed higher level of EGFR protein on membrane and were more sensitive to ADCC activity mediated by cetuximab (P<0.05). The inhibition rate of A549 cells showed no significant difference between transfection group and wild-type group when treated with cetuximab alone (P> 0.05).

CONCLUSIONEGFR expression level influences the sensitivity of A549 lung cancer cell line to ADCC activity mediated by cetuximab but not to cetuximab alone.

Adenocarcinoma ; pathology ; Antibodies, Monoclonal, Humanized ; pharmacology ; Antineoplastic Agents ; pharmacology ; Cetuximab ; Humans ; Immunohistochemistry ; Lung Neoplasms ; pathology ; Receptor, Epidermal Growth Factor ; metabolism ; Tumor Cells, Cultured

OBJECTIVE: This research aims to investaigate the effect of cetuximab and dendritic cells (DCs) to kill the head and neck squamous cell (HNSCC), in order to provide a new way for the patients of HNSCC. METHOD: DCs were induced from peripheral blood monocytes by rhIL-4, rhGM-CSF and TNF-alpha in vitro, 7days later, detecting the surface marks of DCs for example CD83, CD86, and then using MTT and flow cytometry detecting the effect T lymphocytes induced by DCs combining cetuximab to kill HNSCC; EGFR and pEGFR in each group were anlysised by Western blot. RESULT: It is successful to induce DCs in vitro. Mature DCs (mDCs) expressed the suface mark such as CD83, CD86 higher compared with immature DCs (imDCs). Compared with other groups, cetuximab combined with DCs significantly enhanced the cytotoxicty and apoptosis to HNSCC (P < 0.05). pEGFR were gradually reduced as the concenetration of cetuximab increasing (P < 0.05). However, comparing with the group of cetuximab, the group of cetuximab combined with DC has no significant difference at the same concentration of cetuximab. In each group EGFR also has no significant diference (P > 0.05). CONCLUSION Cetuximab and DCs have synergistic effects, which can significantly enhance the killing effect of HNSCC.
Antibodies, Monoclonal, Humanized ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Squamous Cell ; pathology ; Cetuximab ; Dendritic Cells ; immunology ; Head and Neck Neoplasms ; pathology ; Humans ; Squamous Cell Carcinoma of Head and Neck ; Tumor Cells, Cultured

OBJECTIVE: To determine an approach enriching cancer stem cells from laryngeal cancer cell line. To investigate whether laryngeal cancer stem cells in chemoradiotherapy have the characteristic of resistance. METHOD: CD133+ cells and CD133- cells was detected and isolated from Hep-2 cell line by fluorescence activated cell sorting technology. The cytotoxicities of cisplatin and radiation were investigated by cell counting kit-8(CCK-8) assay. The apoptosis and cell cycle was analyzed with flow cytometry. RESULT: CD133+ cells accounted for a fraction of (2.43 +/- 0.77)% in Hep-2 cell line. CD133+ cells have a more obvious characteristics of cancer stem cells. Different cisplatin and radiation concentrations of for two cell have inhibition, in a certain concentration range and the dosage dependence. Cisplatin and radiation had synergistic inhibitory effects with CD133- cells on the growth of two cell. Moreover, cell cycle arrest at G0/G1 phase and more apoptosis was induced by synergistic combination. Different concentrations of cetuximab for Hep-2 cells have inhibition, in a certain concentration range and time and the dosage dependence. The half maxial inhibitory concentration (IC50) of cetuximab to Hep-2 cells on 24 h was 1 036.84 microg/L. Cisplatin and radiation had synergistic inhibitory effects with cetuximab on the growth of Hep-2 cell line. Moreover, cell cycle arrest at G0/G1 phase and more apoptosis was induced by synergistic combination. CONCLUSION Compared with CD133- cells, CD133+ cells subpopulation exhibited extraordinary cancer stem.
AC133 Antigen ; Antibodies, Monoclonal, Humanized ; pharmacology ; Antigens, CD ; analysis ; Antineoplastic Agents ; pharmacology ; Apoptosis ; Cell Cycle ; Cell Line, Tumor ; Cetuximab ; Chemoradiotherapy ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; Flow Cytometry ; Glycoproteins ; analysis ; Humans ; Laryngeal Neoplasms ; therapy ; Neoplastic Stem Cells ; drug effects ; radiation effects ; Peptides ; analysis ; Radiation Tolerance

OBJECTIVE: To determine the sensitivity of cetuximab induced apoptosis in laryngeal squamous carcinoma cells Hep-2, and to evaluate the synergistic killing effects and regulation mechanism of cetuximab alone or cetuximab in combination with chemotherapeutic agents (cisplatin) or radiation means on Hep-2 cells. METHOD: To investigate the cytotoxicities of cetuximab, cisplatin and radiation, cell counting kit-8 (CCK-8) assay was used for the detection of cell growth inhibition ratio, and fluorescence activated cell sorter FACS for the apoptotic rate and cell cycle distribution. RESULT: Cetuximab had inhibitive effect on Hep-2 cells within a certain range of concentration in a time- and dose-dependence manner. The inhibition concentration 50% (IC50) of cetuximab on Hep-2 cells for 24 h was 1 036.84 microg/ml. For application of cisplatin and radiation, the apoptotic rate of Hep-2 cell was higher by combining with cetuximab than their single or combined administration. Moreover, the cell cycle arrested at G0/G1 phase. CONCLUSION Laryngeal cancer Hep-2 cells was sensitive to the cetuximab induced apoptosis. Cetuximab combined with cisplatin and/or radiation can increase the antiproliferative effects on Hep-2 cells. These findings suggest the synergistic combination of cetuximab and cytotoxic agents was sequence depended.
Antibodies, Monoclonal, Humanized ; pharmacology ; Apoptosis ; drug effects ; radiation effects ; Cell Line, Tumor ; Cetuximab ; Cisplatin ; pharmacology ; Combined Modality Therapy ; Humans

Apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can be regulated by the epidermal growth factor (EGF) signaling pathway. In this study, recombinant adenoviral vectors that encode TRAIL gene from the hTERT/RGD promoter (AdTRAIL) was combined with drugs including gefitinib, elotinib, and cetuximab that inhibit EGFR and the EGF signaling pathway in non-small cell lung cancer (NSCLC) cell lines to investigate their antitumor activity. In vitro, compared to single reagent, AdTRAIL combined with EGFR inhibitors reduced proliferation and enhanced apoptosis in H460, A549, and SW1573 cell lines. Western blot results suggested that these effects were relative to up-regulation of pro-apoptosis protein BAX and down-regulation of p-AKT. In vivo, AdTRAIL combined with cetuximab resulted in a significant growth reduction in H460 xenografts without damage to the main organs of nude mice. Histological examination and TUNEL analyses of xenografts showed that cetuximab enhanced cell apoptosis induced by AdTRAIL. These results indicate that EGFR inhibitors enhanced AdTRAIL anti-tumor activity in NSCLC cell lines and that inhibiting the AKT pathway played an important role in this enhancement.
Adenoviridae ; genetics ; Animals ; Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; pharmacology ; Apoptosis ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Cetuximab ; Drug Synergism ; Erlotinib Hydrochloride ; Female ; Genetic Therapy ; Genetic Vectors ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Mice ; Mice, Nude ; Protein Kinase Inhibitors ; pharmacology ; Proto-Oncogene Proteins c-akt ; metabolism ; Quinazolines ; pharmacology ; Receptor, Epidermal Growth Factor ; antagonists & inhibitors ; Recombinant Proteins ; genetics ; metabolism ; Signal Transduction ; TNF-Related Apoptosis-Inducing Ligand ; genetics ; metabolism ; physiology ; Transfection ; Tumor Burden ; Xenograft Model Antitumor Assays ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo explore the changes of the sensitivity of cetuximab-resistant human nasopharyngeal carcinoma (hNPC) cells 5-8F/Erbitux to cetuximab by silencing H-ras gene with RNA interference (RNAi).

METHODSThe 5-8F/Erbitux cells were induced by stepwise exposure to increasing doses of cetuximab. Western blot was conducted to detect the protein levels of H-ras and K-ras. Real-time PCR was employed to detect the expression of H-ras and K-ras. H-ras-shRNA plasmids (shRNA vector carrying the H-ras gene) were constructed and transferred into 5-8F/Erbitux cells. The gene and protein expression levels of H-ras and the changes of the sensitivity of 5-8F/Erbitux cells to cetuximab after transfection were measured, respectively.

RESULTSAfter treatment with cetuximab for 3 and 5 days, the resistance index (RI) of the 5-8F/Erbitux cells was 1.2 and 1.1, and the protein levels of H-ras and K-ras in 5-8F/Erbitux cells were 0.798 +/- 0.019 and 0.190 +/- 0.011, respectively, significantly higher than that in the 5-8F cells (P<0.001). The gene expressions of H-ras and K-ras in 5-8F/Erbitux cells were 1.260 +/- 0.114 and 0.850 +/- 0.006, respectively. Compared with 5-8F cells, the former was higher (P = 0.016) and the latter was lower (P = 0.000). After transfection with H-ras-shRNA plasmid, the 5-8F/Erbitux cells showed reduced levels of H-ras gene and protein, and the cell apoptosis and inhibition rates increased significantly (P<0.001).

CONCLUSIONSH-ras siRNA can reverse cetuximab-resistance of 5-8F/Erbitux cells through down-regulation of H-ras gene expression, indicating that the generation of cetuximab-resistance in 5-8F/Erbitux cells is associated with amplification and overexpression of the H-ras gene.

Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; pharmacology ; Apoptosis ; Carcinoma ; Cell Line, Tumor ; Cell Proliferation ; Cetuximab ; Drug Resistance, Neoplasm ; Gene Expression Regulation, Neoplastic ; Genes, ras ; Humans ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; Plasmids ; Proto-Oncogene Proteins p21(ras) ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection