Synthesis and biological assay of erlotinib analogues and BSA-conjugated erlotinib analogue.

A series of erlotinib analogues that have structural modification at 6,7-alkoxyl positions is efficiently synthesized. The in vitro anti-tumor activity of synthesized compounds is studied in two non-small cell lung cancer (NSCLC) cell lines (A549 and H1975). Among the synthesized compounds, the iodo compound 6 (ETN-6) exhibits higher anti-cancer activity compared to erlotinib. An efficient method is developed for the conjugation of erlotinib analogue-4, alcohol compound, with protein, bovine serum albumin (BSA), via succinic acid linker. The in vitro anti-tumor activity of the protein attached erlotinib analogue, 8 (ETN-4-Suc-BSA), showed stronger inhibitory activity in both A549 and H1975 NSCLC cell lines.

Microwave-assisted efficient conjugation of nanodiamond and paclitaxel.

Nanodiamond has recently received considerable attention due to the various possible applications in medical field such as drug delivery and bio-labeling. For this purpose suitable and effective surface functionalization of the diamond material are required. A versatile and reproducible surface modification method of nanoscale diamond is essential for functionalization. We introduce the input of microwave energy to assist the functionalization of nanodiamond surface. The feasibility of such a process is illustrated by comparing the biological assay of ND-paclitaxel synthesized by conventional and microwave irradiating. Using a microwave we manage to have approximately doubled grafted molecules per nanoparticle of nanodiamond.

Expression of survivin and p53 modulates honokiol-induced apoptosis in colorectal cancer cells.

Honokiol is a small biphenolic compound, which exerts antitumor activities; however, the precise mechanism of honokiol-induced apoptosis in the human colorectal cancer cells remains unclear. Here, we show that survivin and p53 display the opposite role on the regulation of honokiol-induced apoptosis in the human colorectal cancer cells. Honokiol induced the cell death and apoptosis in various colorectal cancer cell lines. Moreover, honokiol elicited the extrinsic death receptor pathway of DR5 and caspase 8 and the intrinsic pathway of caspase 9. The common intrinsic and extrinsic downstream targets of activated caspase 3 and PARP protein cleavage were induced by honokiol. Interestingly, honokiol reduced anti-apoptotic survivin protein and gene expression. Transfection with a green fluorescent protein (GFP)-survivin-expressed vector increased the colorectal cancer cell viability and resisted the honokiol-induced apoptosis. Meantime, honokiol increased total p53 and the phosphorylated p53 proteins at Ser15 and Ser46. The p53-wild type colorectal cancer cells were exhibited greater cytotoxicity, apoptosis and survivin reduction than the p53-null cancer cells after treatment with honokiol. Together, these findings demonstrate that the existence of survivin and p53 can modulate the honokiol-induced apoptosis in the human colorectal cancer cells.

Optimization of gefitinib analogues with potent anticancer activity.

The interactions of gefitinib (Iressa) in EGFR are hydrogen bonding and van der Waals forces through quinazoline and aniline rings. However the morpholino group of gefitinib is poorly ordered due to its weak electron density. A series of novel piperazino analogues of gefitinib where morpholino group substituted with various piperazino groups were designed and synthesized. Most of them indicated significant anti-cancer activities against human cancer cell lines. In particular, compounds 52-54 showed excellent potency against cancer cells. Convergent synthetic approach has been developed for the synthesis of gefitinib intermediate which can lead to gefitinib as well as numerous analogues.

Origami-Inspired Conductive Paper-Based Folded Pressure Sensor with Interconnection Scaling at the Crease for Novel Wearable Applications.

Drawing inspiration from origami structures, a pressure sensor was developed with unique interconnection scaling at its creases crafted on a conductive paper substrate, paving the way for advanced wearable technology. Two screen-printed conductive paper substrates were combined face-to-face, and specific folds were introduced to optimize the sensor structure. The Electrical Contact Resistance (ECR) was systematically analyzed across different fold numbers and crease gaps, revealing a notable trade-off: while increasing the number of folds expanded the sensing area, it also influenced the ECR, reaching a performance plateau. Strategic modifications in the sensor's design, including refining interconnections at the crease, enhanced its sensitivity and stability, culminating in a remarkable sensitivity of 3.75 kPa-1 at subtle pressure levels (0-0.05 kPa). This sensor's real-world applications proved to be transformative, from detecting bruxism and aiding in neck posture correction to remotely sensing trigger finger locking phenomena, highlighting its potential as a pivotal tool in upcoming medical diagnostics and treatments.

CR108, a novel vitamin K3 derivative induces apoptosis and breast tumor inhibition by reactive oxygen species and mitochondrial dysfunction.

Vitamin K3 derivatives have been shown to exert anticancer activities. Here we show a novel vitamin K3 derivative (S)-2-(2-hydroxy-3-methylbutylthio)naphthalene-1,4-dione, which is named as CR108 that induces apoptosis and tumor inhibition through reactive oxygen species (ROS) and mitochondrial dysfunction in human breast cancer. CR108 is more effective on the breast cancer cell death than other vitamin K3 derivatives. Moreover, CR108 induced apoptosis in both the non-HER-2-overexpressed MCF-7 and HER-2-overexpressed BT-474 breast cancer cells. CR108 caused the loss of mitochondrial membrane potential, cytochrome c released from mitochondria to cytosol, and cleaved PARP proteins for apoptosis induction. CR108 markedly increased ROS levels in breast cancer cells. N-acetylcysteine (NAC), a general ROS scavenger, completely blocked the CR108-induced ROS levels, mitochondrial dysfunction and apoptosis. Interestingly, CR108 increased the phosphorylation of p38 MAP kinase but conversely inhibited the survivin protein expression. NAC treatment prevented the activation of p38 MAP kinase and rescued the survivin protein levels. SB202190, a specific p38 MAP kinase inhibitor, recovered the survivin protein levels and attenuated the cytotoxicity of CR108-treated cells. Furthermore, CR108 inhibited the xenografted human breast tumor growth in nude mice. Together, we demonstrate that CR108 is a novel vitamin K3 derivative that induces apoptosis and tumor inhibition by ROS production and mitochondrial dysfunction and associates with the phosphorylation of p38 MAP kinase and the inhibition of survivin in the human breast cancer.

Osimertinib Induces the Opposite Effect of Proliferation and Migration in the Drug Resistance of EGFR-T790M Non-small Cell Lung Cancer Cells.

BACKGROUND: Lung cancer has become one of the leading causes of cancer incidence and mortality worldwide. Non-small cell lung carcinoma (NSCLC) is the most common type among all lung cancer cases. NSCLC patients contained high levels of activating epidermal growth factor receptor (EGFR) mutations, such as exon 19 deletion, L858R and T790M. Osimertinib, a third-generation of EGFR tyrosine kinase inhibitor (EGFR-TKI), has therapeutic efficacy on the EGFR-T790M mutation of NSCLC patients; however, treatment of osimertinib still can induce drug resistance in lung cancer patients. Therefore, investigation of the drug resistance mechanisms of osimertinib will provide novel strategies for lung cancer therapy. METHODS: The H1975OR osimertinib-resistant cell line was established by prolonged exposure with osimertinib derived from the H1975 cells. The cell proliferation ability was evaluated by the cell viability and cell growth assays. The cell migration ability was determined by the Boyden chamber assays. The differential gene expression profile was analyzed by genome-wide RNA sequencing. The protein expression and location were analyzed by western blot and confocal microscopy. RESULTS: In this study, we established the osimertinib-resistant H1975 (T790M/L858R) cancer cells, named the H1975OR cell line. The cell growth ability was decreased in the H1975OR cells by comparison with the H1975 parental cells. Conversely, the cell migration ability was elevated in the H1975OR cells. We found the differential gene expression profile of cell proliferation and migration pathways between the H1975OR and H1975 parental cells. Interestingly, the protein levels of phospho-EGFR, PD-L1, E-cadherin and ß-catenin were decreased, but the survivin and N-cadherin proteins were increased in the H1975OR drug-resistant cells. CONCLUSION: Osimertinib induces the opposite effect of proliferation and migration in the drug resistance of EGFRT790M lung cancer cells. We suggest that differential gene and protein expressions in the cell proliferation and migration pathways may mediate the drug resistance of osimertinib in lung cancer cells. Understanding the molecular drugresistant mechanisms of proliferation and migration pathways of osimertinib may provide novel targets and strategies for the clinical treatment of EGFR-TKIs in lung cancer patients.

Enhancing Efficacy of Albumin-Bound Paclitaxel for Human Lung and Colorectal Cancers through Autophagy Receptor Sequestosome 1 (SQSTM1)/p62-Mediated Nanodrug Delivery and Cancer therapy.

Selective autophagy is a defense mechanism by which foreign pathogens and abnormal substances are processed to maintain cellular homeostasis. Sequestosome 1 (SQSTM1)/p62, a vital selective autophagy receptor, recruits ubiquitinated cargo to form autophagosomes for lysosomal degradation. Nab-PTX is an albumin-bound paclitaxel nanoparticle used in clinical cancer therapy. However, the role of SQSTM1 in regulating the delivery and efficacy of nanodrugs remains unclear. Here we showed that SQSTM1 plays a crucial role in Nab-PTX drug delivery and efficacy in human lung and colorectal cancers. Nab-PTX induces SQSTM1 phosphorylation at Ser403, which facilitates its incorporation into the selective autophagy of nanoparticles, known as nanoparticulophagy. Nab-PTX increased LC3-II protein expression, which triggered autophagosome formation. SQSTM1 enhanced Nab-PTX recognition to form autophagosomes, which were delivered to lysosomes for albumin degradation, thereby releasing PTX to induce mitotic catastrophe and apoptosis. Knockout of SQSTM1 downregulated Nab-PTX-induced mitotic catastrophe, apoptosis, and tumor inhibition in vitro and in vivo and inhibited Nab-PTX-induced caspase 3 activation via a p53-independent pathway. Ectopic expression of SQSTM1 by transfection of an SQSTM1-GFP vector restored the drug efficacy of Nab-PTX. Importantly, SQSTM1 is highly expressed in advanced lung and colorectal tumors and is associated with poor overall survival in clinical patients. Targeting SQSTM1 may provide an important strategy to improve nanodrug efficacy in clinical cancer therapy. This study demonstrates the enhanced efficacy of Nab-PTX for human lung and colorectal cancers via SQSTM1-mediated nanodrug delivery.

A lesion-selective albumin-CTLA4Ig as a safe and effective treatment for collagen-induced arthritis.

BACKGROUND: CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG1 that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment. METHODS: We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis. RESULTS: Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice. CONCLUSIONS: Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

MicroRNA-30a inhibits cell migration and invasion by downregulating vimentin expression and is a potential prognostic marker in breast cancer.

Tumor recurrence and metastasis result in an unfavorable prognosis for cancer patients. Recent studies have suggested that specific microRNAs (miRNAs) may play important roles in the development of cancer cells. However, prognostic markers and the outcome prediction of the miRNA signature in breast cancer patients have not been comprehensively assessed. The aim of this study was to identify miRNA biomarkers relating to clinicopathological features and outcome of breast cancer. A miRNA microarray analysis was performed on breast tumors of different lymph node metastasis status and with different progression signatures, indicated by overexpression of cyclin D1 and ß-catenin genes, to identify miRNAs showing a significant difference in expression. The functional interaction between the candidate miRNA, miR-30a, and the target gene, Vim, which codes for vimentin, a protein involved in epithelial-mesenchymal transition, was examined using the luciferase reporter assay, western blotting, and migration and invasion assays. The association between the decreased miR-30a levels and breast cancer progression was examined in a survival analysis. miR-30a negatively regulated vimentin expression by binding to the 3'-untranslated region of Vim. Overexpression of miR-30a suppressed the migration and invasiveness phenotypes of breast cancer cell lines. Moreover, reduced tumor expression of miR-30a in breast cancer patients was associated with an unfavorable outcome, including late tumor stage, lymph node metastasis, and worse progression (mortality and recurrence) (p < 0.05). In conclusion, these findings suggest a role for miR-30a in inhibiting breast tumor invasiveness and metastasis. The finding that miR-30a downmodulates vimentin expression might provide a therapeutic target for the treatment of breast cancer.

Targeting EGFR and Monitoring Tumorigenesis of Human Lung Cancer Cells In Vitro and In Vivo Using Nanodiamond-Conjugated Specific EGFR Antibody.

Nanoprobes provide advantages for real-time monitoring of tumor markers and tumorigenesis during cancer progression and development. Epidermal growth factor receptor (EGFR) is a key protein that plays crucial roles for tumorigenesis and cancer therapy of lung cancers. Here, we show a carbon-based nanoprobe, nanodiamond (ND), which can be applied for targeting EGFR and monitoring tumorigenesis of human lung cancer cells in vitro and in vivo. The optimal fluorescent intensities of ND particles were observed in the human lung cancer cells and nude mice under in vivo imaging system. The fluorescence signal of ND particles can be real-time detected in the xenografted human lung tumor formation of nude mice. Moreover, the ND-conjugated specific EGFR antibody cetuximab (Cet) can track the location and distribution of EGFR proteins of lung cancer cells in vitro and in vivo. ND-Cet treatment increased cellular uptake ability of nanocomposites in the EGFR-expressed cells but not in the EGFR-negative lung cancer cells. Interestingly, single ND-Cet complex can be directly observed on the protein G bead by immunoprecipitation and confocal microscopy. Besides, the EGFR proteins were transported to lysosomes for degradation. Together, this study demonstrates that ND-conjugated Cet can apply for targeting EGFR and monitoring tumorigenesis during lung cancer progression and therapy.

Co-inhibition of Aurora A and Haspin kinases enhances survivin blockage and p53 induction for mitotic catastrophe and apoptosis in human colorectal cancer.

Colorectal cancer (CRC) is a leading cause and mortality worldwide. Aurora A and haspin kinases act pivotal roles in mitotic progression. However, the blockage of Aurora A and Haspin for CRC therapy is still unclear. Here we show that the Haspin and p-H3T3 protein levels were highly expressed in CRC tumor tissues of clinical patients. Overexpression of Haspin increased the protein levels of p-H3T3 and survivin in human CRC cells; conversely, the protein levels of p-H3T3 and survivin were decreased by the Haspin gene knockdown. Moreover, the gene knockdown of Aurora A induced abnormal chromosome segregation, mitotic catastrophe, and cell growth inhibition. Combined targeted by co-treatment of CHR6494, a Haspin inhibitor, and MLN8237, an Aurora A inhibitor, enhanced apoptosis and CRC tumor inhibition. MLN8237 and CHR6494 induced abnormal chromosome segregation and mitotic catastrophe. Meanwhile, MLN8237 and CHR6494 inhibited survivin protein levels but conversely induced p53 protein expression. Ectopic survivin expression by transfection with a survivin-expressed vector resisted the cell death in the MLN8237- and CHR6494-treated cells. In contrast, the existence of functional p53 increased the apoptotic levels by treatment with MLN8237 and CHR6494. Co-treatment of CHR6494 and MLN8237 enhanced the blockage of human CRC xenograft tumors in nude mice. Taken together, co-inhibition of Aurora A and Haspin enhances survivin inhibition, p53 pathway induction, mitotic catastrophe, apoptosis and tumor inhibition that may provide a potential strategy for CRC therapy.

A novel EGFR inhibitor suppresses survivin expression and tumor growth in human gefitinib-resistant EGFR-wild type and -T790M non-small cell lung cancer.

Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are currently used therapy for non-small cell lung cancer (NSCLC) patients; however, drug resistance during cancer treatment is a critical problem. Survivin is an anti-apoptosis protein, which promotes cell proliferation and tumor growth that highly expressed in various human cancers. Here, we show a novel synthetic compound derived from gefitinib, do-decyl-4-(4-(3-(4-(3-chloro-4-fluorophenylamino)-7-methoxyquinazolin-6-yloxy)propyl) piper-azin-1-yl)-4-oxobutanoate, which is named as SP101 that inhibits survivin expression and tumor growth in both the EGFR-wild type and -T790M of NSCLC. SP101 blocked EGFR kinase activity and induced apoptosis in the A549 (EGFR-wild type) and H1975 (EGFR-T790M) lung cancer cells. SP101 reduced survivin proteins and increased active caspase 3 for inducing apoptosis. Ectopic expression of survivin by a survivin-expressed vector attenuated the SP101-induced cell death in lung cancer cells. Moreover, SP101 inhibited the gefitinib-resistant tumor growth in the xenograft human H1975 lung tumors of nude mice. SP101 substantially reduced survivin proteins but conversely elicited active caspase 3 proteins in tumor tissues. Besides, SP101 exerted anticancer abilities in the gefitinib resistant cancer cells separated from pleural effusion of a clinical lung cancer patient. Consistently, SP101 decreased the survivin proteins and the patient-derived xenografted lung tumor growth in nude mice. Anti-tumor ability of SP101 was also confirmed in the murine lung cancer model harboring EGFR T790M-L858R. Together, SP101 is a new EGFR inhibitor with inhibiting survivin that can be developed for treating EGFR wild-type and EGFR-mutational gefitinib-resistance in human lung cancers.

Opposite expression of securin and γ-H2AX regulates baicalein-induced cancer cell death.

Securin and γ-H2AX have been shown to regulate cell survival and genomic stability. However, it is still unknown how the expression and regulation of these proteins is altered following treatment with baicalein, a natural flavonoid extracted from the Scutellaria baicalensis root. In the present study, we investigate the possible roles of securin and γ-H2AX in baicalein-induced cancer cell death. Baicalein reduced cell viability in a variety of human cancer cell lines, including bladder, cervical, colon, and lung cancer cells. Interestingly, baicalein treatment (40-80 µM for 24 h) markedly inhibited securin expression, while the levels of γ-H2AX were elevated. Abnormal spindle formation and chromosomal segregation were induced by baicalein. Furthermore, wild type HCT116 cancer cells had a higher incidence of cytotoxicity and apoptosis than securin-null HCT116 cells following treatment with baicalein. In contrast, baicalein increased the levels of γ-H2AX to a similar extent in both cell types. Transfection with H2AX siRNA further increased baicalein-induced cell death. Additionally, blockade of the AKT pathway by treatment with wortmannin or AKT shRNA lowered the levels of γ-H2AX and enhanced cytotoxicity in baicalein-treated cells. Taken together, our findings suggest that the opposing effects of baicalein on securin and γ-H2AX levels may be involved in the regulation of cell viability and genomic stability by this compound.

Covalent linkage of nanodiamond-paclitaxel for drug delivery and cancer therapy.

A nanoparticle-conjugated cancer drug provides a novel strategy for cancer therapy. In this study, we manipulated nanodiamond (ND), a carbon nanomaterial, to covalently link paclitaxel for cancer drug delivery and therapy. Paclitaxel was bound to the surface of 3-5 nm sized ND through a succession of chemical modifications. The ND-paclitaxel conjugation was measured by atomic force microscope and nuclear magnetic resonance spectroscopy, and confirmed with infrared spectroscopy by the detection of deuterated paclitaxel. Treatment with 0.1-50 microg ml(-1) ND-paclitaxel for 48 h significantly reduced the cell viability in the A549 human lung carcinoma cells. ND-paclitaxel induced both mitotic arrest and apoptosis in A549 cells. However, ND alone or denatured ND-paclitaxel (after treatment with strong alkaline solution, 1 M NaOH) did not induce the damage effects on A549 cells. ND-paclitaxel was taken into lung cancer cells in a concentration-dependent manner using flow cytometer analysis. The ND-paclitaxel particles were located in the microtubules and cytoplasm of A549 cells observed by confocal microscopy. Furthermore, ND-paclitaxel markedly blocked the tumor growth and formation of lung cancer cells in xenograft SCID mice. Together, we provide a functional covalent conjugation of ND-paclitaxel, which can be delivered into lung carcinoma cells and preserves the anticancer activities on the induction of mitotic blockage, apoptosis and anti-tumorigenesis.

Invasiveness and surgical timing evaluation by clinical features of ground-glass opacity nodules in lung cancers.

BACKGROUND: The early stages of lung cancer with ground-glass opacity (GGO) pattern are detectable. However, it remains a challenge for physicians how best to treat GGO nodules as invasive tumors are occasionally found, even in pure GGO nodules. This study identified the invasiveness by the clinical features of the GGO nodules. METHODS: A retrospective review of patients with resected GGO nodules from August 2015 to February 2019 was performed. A total of 92 patients were enrolled and gender, age, tumor location, operation times, tumor size, histopathologic and radiological findings were analyzed. RESULTS: In this study, the sequential of GGO nodules invasiveness was significantly related to the tumor size and solid component. After regrouping the population into preinvasive and invasive groups, the invasiveness was significantly related to tumor size, solid component, tumor volume and maximal computed tomography (CT) value. CONCLUSIONS: The invasiveness is difficult to evaluate according to the CT features only when the GGO nodules are less than 2 cm and consolidation/tumor ratio (C/T ratio) are less than 0.25. Tumor size and solid component are significant factors for predicting invasiveness. Part-solid GGO nodules with a diameter greater than 1 cm require surgical consideration due to their high risk of invasiveness.

Targeting EGFR of triple-negative breast cancer enhances the therapeutic efficacy of paclitaxel- and cetuximab-conjugated nanodiamond nanocomposite.

Breast cancer is the most common malignancy and a leading cause of cancer-related mortality among women worldwide. Triple-negative breast cancer (TNBC) is characterized by the lack of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2). However, epidermal growth factor receptor (EGFR) is highly expressed in most of the TNBCs, which may provide a potential target for EGFR targeting therapy. Nanodiamond (ND) is a carbon-based nanomaterial with several advantages, including fluorescence emission, biocompatibility, and drug delivery applications. In this study, we designed a nanocomposite by using ND conjugated with paclitaxel (PTX) and cetuximab (Cet) for targeting therapy on the EGFR-positive TNBC cells. ND-PTX inhibited cell viability and induced mitotic catastrophe in various human breast cancer cell lines (MDA-MB-231, MCF-7, and BT474); in contrast, ND alone did not induce cell death. ND-PTX inhibited the xenografted human breast tumors in nude mice. We further investigated ND-PTX-Cet drug efficacy on the TNBC of MDA-MB-231 breast cancer cells. ND-PTX-Cet could specifically bind to EGFR and enhanced the anticancer effects including drug uptake levels, mitotic catastrophe, and apoptosis in the EGFR-expressed MDA-MB-231 cells but not in the EGFR-negative MCF-7 cells. In addition, ND-PTX-Cet increased the protein levels of active caspase-3 and phospho-histone H3 (Ser10). Furthermore, ND-PTX-Cet showed more effective on the reduction of TNBC tumor volume by comparison with ND-PTX. Taken together, these results demonstrated that ND-PTX-Cet nanocomposite enhanced mitotic catastrophe and apoptosis by targeting EGFR of TNBC cells, which can provide a feasible strategy for TNBC therapy. STATEMENT OF SIGNIFICANCE: Current TNBC treatment is ineffective against the survival rate of TNBC patients. Therefore, the development of new treatment strategies for TNBC patients is urgently needed. Here, we have designed a nanocomposite by targeting on the EGFR of TNBC to enhance therapeutic efficacy by ND-conjugated PTX and Cet (ND-PTX-Cet). Interestingly, we found that the co-delivery of Cet and PTX by ND enhanced the apoptosis, mitotic catastrophe and tumor inhibition in the EGFR-expressed TNBC in vitro and in vivo. Consequently, this nanocomposite ND-PTX-Cet can be applied for targeting EGFR of human TNBC therapy.

7-Chloro-6-piperidin-1-yl-quinoline-5,8-dione (PT-262), a novel synthetic compound induces lung carcinoma cell death associated with inhibiting ERK and CDC2 phosphorylation via a p53-independent pathway.

BACKGROUND: The derivatives of 5,8-quinolinedione have been shown to exert anticancer activities. A new synthetic compound 7-chloro-6-piperidin-1-yl-quinoline-5,8-dione (designed as PT-262) derived from 6,7-dichloroquinoline-5,8-dione on its anticancer activity was investigated in this study. MATERIALS AND METHODS: PT-262 was synthesized as the following: triethylamine (0.56 ml, 5.1 mmol) was added dropwise to a solution of 6,7-dichloroquinoline-5,8-dione (1.00 g, 4.4 mmol) and piperidine (0.50 ml, 5.1 mmol) in 150 ml of benzene with stirring at room temperature for 5 min, and the solvent was removed using rotary evaporator to give a dark brown solid. PT-262 was purified by flash chromatography using 50% ethyl acetate/hexanes to elute that displayed as brown solids. To examine the induction of apoptosis following PT-262 treatment, the lung cancer cells were subjected to apoptotic cell observation, caspase activation, and mitochondrial functional assays. The protein levels of phosphorylated ERK and CDC2 after treatment with PT-262 were analyzed by Western blot. RESULTS: Treatment with 1-20 microM PT-262 for 24 h induced cytotoxicity via a concentration-dependent manner in human lung cancer cells. PT-262 induced the loss of mitochondrial membrane potential and elevated the caspase-3 activation and apoptosis. Interestingly, the phosphorylation of ERK was inhibited by PT-262. The IC50 value of ERK phosphorylation inhibition was approximate around 5 microM. Treatment with a specific MEK1/2 (the upstream of ERK) inhibitor, PD98059, increased the PT-262-induced cytotoxicity in lung cancer cells. Moreover, PT-262 did not alter the protein expression of tumor suppressor p53. PT-262 elicited the cytotoxicity and accumulated the G2/M fractions in both the p53-wild type and p53-null lung cancer cells. The mitosis-regulated protein levels of cyclin B1 and phospho-CDC2 at Thr14, Tyr15, and Thr161 were repressed by PT-262 in these cells. CONCLUSION: PT-262 suppresses the phosphorylation of ERK and CDC2 associated with proliferation inhibition via a p53-independent pathway in human lung cancer cells.

Celecoxib induces p53-PUMA pathway for apoptosis in human colorectal cancer cells.

Celecoxib, a clinical non-steroidal anti-inflammatory drug, displays anticarcinogenic and chemopreventive activities in human colorectal cancers, although the mechanisms of apoptosis by celecoxib are poorly understood. The existence of functional p53 but not securin in colorectal cancer cells was higher on the induction of cytotoxicity than the p53-mutational colorectal cancer cells following celecoxib treatment. The p53-wild type HCT116 cells were more susceptible to increase approximately 25% cell death than the p53-null HCT116 cells after treatment with 100 microM celecoxib for 24 h. Transfection with a small interfering RNA of p53 reduced the celecoxib-induced cytotoxicity in the RKO (p53-wild type) colorectal cancer cells. Celecoxib (80-100 microM for 24 h) significantly increased total p53 proteins and the phosphorylated p53 proteins at serine-15, -20, -46, and -392 in RKO cells. However, the phospho-p53 (serine-15, -20, and -392) proteins were presented on the nuclei of cells but the phospho-p53 (serine-46) protein was located on the cytoplasma of apoptotic cells following treatment with celecoxib. Interestingly, the p53 up-regulated modulator of apoptosis (PUMA) protein, which located on the mitochondria, was induced by celecoxib in the p53-functional colorectal cancer cells but not in the p53-mutational cells. Together, this study provides the first time that celecoxib induces the various phosphorylated sites of p53 and activates p53-PUMA pathway, which potentiates the apoptosis induction in human colorectal cancer cells.

Regulation of gamma-H2AX and securin contribute to apoptosis by oxaliplatin via a p38 mitogen-activated protein kinase-dependent pathway in human colorectal cancer cells.

Oxaliplatin, a chemotherapeutic drug, induces DNA strand breaks leading to apoptosis in colorectal cancer cells. gamma-H2AX is a phosphorylated histone H2AX that can act as a marker of DNA double-strand breaks (DSBs). It has been shown that securin proteins were over-expressed in a variety of cancer cells. However, the roles of gamma-H2AX and securin on the oxaliplatin-induced apoptosis in human colorectal cancer cells remain unclear. Treatment of oxaliplatin (1-10 microM for 6-24h) persistently induced gamma-H2AX formation and inhibited securin protein expression via a time- and concentration-dependent manner in HCT116 securin-wild type colorectal cancer cells. Compared with HCT116 securin-wild type cells, the induction of apoptosis and persistent gamma-H2AX formation by oxaliplatin was reduced in the HCT116 securin-null colorectal cancer cells. Furthermore, the blockage of caspases by specific caspase inhibitors reduced the levels of gamma-H2AX proteins and cytotoxicity but increased securin protein expression in the oxaliplatin-exposed cells. The gene knockdown of H2AX by transfection with a short interfering RNA of H2AX enhanced the oxaliplatin-induced cell death. Interestingly, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was markedly increased by oxaliplatin. Pre-treatment of a specific p38 MAPK inhibitor SB202190 reduced gamma-H2AX proteins and increased securin protein expression in the oxaliplatin-treated cells. Our findings suggest that p38 MAPK may oppositely regulate securin protein expression and gamma-H2AX formation in the oxaliplatin-induced apoptosis of human colorectal cancer cells.