In vitro antiproliferative effect of trastuzumab (Herceptin(®)) combined with cetuximab (Erbitux(®)) in a model of human non-small cell lung cancer expressing EGFR and HER2

p70S6K/Akt dual inhibitor DIACC3010 is efficacious in preclinical models of gastric cancer alone and in combination with trastuzumab

The PI3K-Akt-mTOR (PAM) pathway is implicated in tumor progression in many tumor types, including metastatic gastric cancer (GC). The initial promise of PAM inhibitors has been unrealized in the clinic, presumably due, in part, to the up-regulation of Akt signaling that occurs when the pathway is inhibited. Here we present that DIACC3010 (formerly M2698), an inhibitor of two nodes in the PAM pathway, p70S6K and Akt 1/3, blocks the pathway in in vitro and in vivo preclinical models of GC while providing a mechanism that inhibits signaling from subsequent Akt up-regulation. Utilizing GC cell lines and xenograft models, we identified potential markers of DIACC3010-sensitivity in Her2-negative tumors, i.e., PIK3CA mutations, low basal pERK, and a group of differentially expressed genes (DEGs). The combination of DIACC3010 and trastuzumab was evaluated in Her2-positive cell lines and models. Potential biomarkers for the synergistic efficacy of the combination of DIACC3010 + trastuzumab also included DEGs as well as a lack of up-regulation of pERK. Of 27 GC patient-derived xenograft (PDX) models tested in BALB/c nu/nu mice, 59% were sensitive to DIACC3010 + trastuzumab. Of the 21 HER2-negative PDX models, DIACC3010 significantly inhibited the growth of 38%. Altogether, these results provide a path forward to validate the potential biomarkers of DIACC3010 sensitivity in GC and support clinical evaluation of DIACC3010 monotherapy and combination with trastuzumab in patients with HER2- negative and positive advanced GCs, respectively.

Chemical, Antioxidant and Biological Studies of Brassica incana subsp. raimondoi (Brassicaceae) Leaf Extract

Brassica incana subsp. raimondoi is an endemic taxon present in a restricted area located on steep limestone cliffs at an altitude of about 500 m a.s.l. in eastern Sicily. In this research, for the first time, studies on the phytochemical profile, the antioxidant properties in cell-free and cell-based systems, the cytotoxicity on normal and cancer cells by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, and on Artemia salina Leach, were performed. The total phenolic, flavonoid, and condensed tannin contents of the leaf hydroalcoholic extract were spectrophotometrically determined. Ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) analysis highlighted the presence of several phenolic acids, flavonoids, and carotenoids, while High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) identified various kaempferol and isorhamnetin derivatives. The extract exhibited different antioxidant properties according to the five in vitro methods used. Cytotoxicity by MTT assay evidenced no impact on normal human fibroblasts (HFF-1) and prostate cancer cells (DU145), and cytotoxicity accompanied by necrotic cell death for colon cancer cells (CaCo-2) and hepatoma cells (HepG2), starting from 100 μg/mL and 500 μg/mL, respectively. No cytotoxic effects were detected by the A. salina lethality bioassay. In the H₂O₂-induced oxidative stress cell model, the extract counteracted cellular reactive oxygen species (ROS) production and preserved non-protein thiol groups (RSH) affected by H₂O₂ exposure in HepG2 cells. Results suggest the potential of B. incana subsp. raimondoi as a source of bioactive molecules.

Biodistribution, pharmacokinetics and radioimmunotherapy of 188Re-cetuximab in NCI-H292 human lung tumor-bearing nude mice

Background Cetuximab is a fully humanized IgG1 subclass monoclonal that binds specifically to the human epidermal growth factor receptor (EGFR). Although EGFR is expressed in normal cells, the overexpression of EGFR is detected in many human cancers, such as colon, rectum and lung tumors. In this study, cetuximab with a combination of radiotherapy nuclear ¹⁸⁸Re achieved better therapeutic effect on lung cancer. Methods¹⁸⁸Re-cetuximab administered by the i.v. route in human NCI-H292 lung tumor-bearing mice was investigated. NanoSPECT/CT images were taken to evaluate the distribution and tumor targeting of ¹⁸⁸Re-cetuximab in mice. The anti-tumor effect of ¹⁸⁸Re-cetuximab was assessed by the tumor growth inhibition, survival ratio. Results For nanoSPECT/CT imaging, a significant uptake in tumor was observed at 24 and 48 h following the injection of ¹⁸⁸Re-cetuximab. The anti-tumor effect of ¹⁸⁸Re-cetuximab was assessed by tumor growth inhibition and the survival ratio. The tumor-bearing mice treated with ¹⁸⁸Re-cetuximab showed a better mean tumor growth inhibition rate (MGI = 0.049) and longer median survival time and lifespan (62.50 d; 70.07%) than those treated with ¹⁸⁸Re-perrhenate and cetuximab only by single injection. A synergistic effect of tumor growth inhibition was observed with the combination index exceeding one for ¹⁸⁸Re-cetuximab (CI = 6.135 and 9.276). Conclusion The tumor targeting and localization of 188Re-cetuximab were confirmed in this study. Synergistic therapeutic efficacy was demonstrated for the radioimmunotherapy of ¹⁸⁸Re-cetuximab. The results of this study reveal the potential advantage and benefit obtained from ¹⁸⁸Re-cetuximab for diagnosis and therapy of oncology applications in the future.

PlncRNA-1 induces apoptosis through the Her-2 pathway in prostate cancer cells

To determine whether PlncRNA-1 induces apoptosis in prostate cancer cells through the Her-2 pathway. The expression of PlncRNA-1, Her-2, and related cyclin proteins in 23 cases of prostate cancer and adjacent normal tissues was analyzed and compared. LNCaP cells were divided into a control group and an LNCaP-PlncRNA-1-siRNA experimental group. Normal prostate RWPE-1 cells were divided into an RWPE-1 control group and an RWPE-1-PlncRNA-1 experimental group. After PlncRNA-1 silencing and overexpression, changes in Her-2 and cyclinD1 expression levels were detected both in vivo and in vitro. In prostate cancer tissues, Her-2 and PlncRNA-1 were highly expressed and significantly correlated. In LNCaP cells, the expression of Her-2 and cyclinD1 decreased following the downregulation of PlncRNA-1 as assessed by real-time PCR and Western blotting. In RWPE-1 cells, the expression of Her-2 and cyclinD1 increased following PlncRNA-1 overexpression. Flow cytometry revealed that the proportion of LNCaP cells in G2/M phase was significantly increased after PlncRNA-1 silencing and that the proportion of RWPE-1 cells in G2/M phase was significantly decreased after PlncRNA-1 overexpression. Furthermore, animal experiments validated these results. In conclusion, in prostate cancer, PlncRNA-1 regulates the cell cycle and cyclinD1 levels and can also regulate proliferation and apoptosis in prostate cancer cells through the Her-2 pathway.

Tumor-penetration and antitumor efficacy of cetuximab are enhanced by co-administered iRGD in a murine model of human NSCLC

Lung cancer is the leading cause of cancer-associated mortality, worldwide. For this reason, novel therapies are required for the treatment of this devastating disease. Cetuximab is a monoclonal antibody against epidermal growth factor receptor (EGFR), which is overexpressed in a variety of solid tumors, including non-small cell lung cancer (NSCLC). The therapeutic efficacy of cetuximab for NSCLC is limited to use as a monotherapy or in combination with chemotherapy. The objective of the present study was to develop a novel strategy to enhance the therapeutic efficacy of cetuximab for NSCLC by a co-administration with the tumor-penetrating internalizing RGD peptide (iRGD). Human NSCLC subcutaneous xenograft models established with the A549 cell line in nude mice were treated with 30 mg/kg cetuximab, 4 mg/kg iRGD, cetuximab plus iRGD or phosphate-buffered saline. The tumor-penetration, in vivo therapeutic efficacy and involved mechanism were evaluated. The present study showed that the A549 xenograft model is sensitive to the co-administration of cetuximab and iRGD. Treatment with cetuximab plus iRGD resulted in a significant increase in the tumor-penetration of cetuximab and tumor reduction compared with cetuximab monotherapy. In conclusion, iRGD enhances the effects of co-administered cetuximab in an NSCLC model. The combined application of cetuximab and iRGD may be a novel strategy to enhance the clinical therapeutic efficacy of cetuximab for the treatment of NSCLC.

Lapatinib-induced mesenchymal-epithelial transition in squamous cell carcinoma cells correlates with unexpected alteration of β-catenin expression

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer progression, and may promote resistance of cancer cells to therapy. Inhibiting EMT appears to be crucial to inhibit drug resistance. The mesenchymal-epithelial transition (MET), which is the reverse program of EMT in metastases, is characterized by the upregulation of epithelial adhesive proteins such as E-cadherin, and downregulation of mesenchymal proteins such as vimentin. The sensitivity of cancer cells to epithelial growth factor receptor (EGFR) inhibitor may be increased by inducing MET in these cells. Therefore, it is of clinical importance to specify the phenotype of cancer cells in order to overcome the phenomenon of drug resistance. The aim of the present study was to investigate the expression pattern of specific markers in squamous cell carcinoma (SCC) cells following stimulation with lapatinib and gefitinib. For this purpose, the head and neck (HN) SCC cell lines HNSCC22B and HNSCC11A were incubated with 0.5 and 2 µg/ml lapatinib and gefitinib, and the levels of E-cadherin, vimentin, matrix metalloproteinase-14, c-kit and β-catenin were detected by immunocytochemistry and enzyme-linked immunosorbent assay at 5, 24 and 96 h post-incubation. The results indicated that, compared with HNSCC22B cells, the protein expression levels of vimentin increased, whereas those of E-cadherin reduced, in non-stimulated HNSCC11A cells. In addition, the protein expression levels of β-catenin were altered in the epithelial- and mesenchymal-associated SCC cell lines following treatment with lapatinib and gefitinib. Furthermore, lapatinib induced the downregulation of vimentin and upregulation of E-cadherin in HNSCC11A cells in a time-dependent manner. This suggests that the sensitivity of cancer cells to lapatinib may be improved by inducing MET in these cells. In summary, the results of the present study demonstrated that lapatinib-induced MET led to an unexpected alteration of the protein expression levels of β-catenin in SCC cells. Further studies on the mechanistic role of MET are required in order to increase the sensitivity of cancer cells to EGFR inhibitor and block the EMT process in these cells.

Anti-Tumor Effects of Peptide Therapeutic and Peptide Vaccine Antibody Co-targeting HER-1 and HER-2 in Esophageal Cancer (EC) and HER-1 and IGF-1R in Triple-Negative Breast Cancer (TNBC)

Despite the promise of targeted therapies, there remains an urgent need for effective treatment for esophageal cancer (EC) and triple-negative breast cancer (TNBC). Current FDA-approved drugs have significant problems of toxicity, safety, selectivity, efficacy and development of resistance. In this manuscript, we demonstrate that rationally designed peptide vaccines/mimics are a viable therapeutic strategy for blocking aberrant molecular signaling pathways with high affinity, specificity, potency and safety. Specifically, we postulate that novel combination treatments targeting members of the EGFR family and IGF-1R will yield significant anti-tumor effects in in vitro models of EC and TNBC possibly overcoming mechanisms of resistance. We show that the combination of HER-1 and HER-2 or HER-1 and IGF-1R peptide mimics/vaccine antibodies exhibited enhanced antitumor properties with significant inhibition of tumorigenesis in OE19 EC and MDA-MB-231 TNBC cell lines. Our work elucidates the mechanisms of HER-1/IGF-1R and HER-1/HER-2 signaling in these cancer cell lines, and the promising results support the rationale for dual targeting with HER-1 and HER-2 or IGF-1R as an improved treatment regimen for advanced therapy tailored to difference types of cancer.