salvador Promotes both cell cycle exit and apoptosis in Drosophila and is mutated in human cancer cell lines

The number of cells in an organism is determined by regulating both cell proliferation and cell death. Relatively few mechanisms have been identified that can modulate both of these processes. In a screen for Drosophila mutations that result in tissue overgrowth, we identified salvador (sav), a gene that promotes both cell cycle exit and cell death. Elevated Cyclin E and DIAP1 levels are found in mutant cells, resulting in delayed cell cycle exit and impaired apoptosis. Salvador contains two WW domains and binds to the Warts (or LATS) protein kinase. The human ortholog of salvador (hWW45) is mutated in three cancer cell lines. Thus, salvador restricts cell numbers in vivo by functioning as a dual regulator of cell proliferation and apoptosis.     

Rapid induction of apoptosis in human gastric cancer cell lines by sorbitol

Most solid tumors, including gastric cancers, respond poorly to non-surgical treatments which are expected to induce an apoptosis-dependent involution. We hypothesize that the apoptotic machinery in solid tumors is either defective or in a suppressed condition. Overcoming the ineffective induction of apoptosis may improve the responsiveness of solid tumors to non-surgical treatments. Recently, sorbitol, a kind of hexose, has been found to be an effective inducer of apoptosis in HEp-2 cells. Therefore, it is of particular interest to examine the effect of sorbitol-treatment on gastric cancer cells. In the present study, we selected 4 gastric cancer cell lines which have been reported to exhibit different abilities in regard to apoptosis induction, and examined the effect of sorbitol-treatment on apoptosis induction. Within 3 hr after sorbitol-treatment, apoptosis was induced comparably in all cell lines examined. Cell death in MKN-1, MKN-28 or MKN-74 proceeded in a biphasic manner, while cell death in KATO-III was monophasic. The cell death partially depended on caspase activity. Treatments with sorbitol in combination with 12-O-tetradecanoylphorbol-13-acetate (TPA) markedly suppressed the apoptotic cell death, suggesting a role of protein kinase-C-dependent process. To our knowledge, this is the most rapid induction of apoptosis in human gastric cancer cells reported to date.     

Phenylpropanoids from Juglans mandshurica exhibit cytotoxicities on liver cancer cell lines through apoptosis induction

Three new phenylpropanoids (1–3) together with six known congeners (4–9) were isolated from the bark of Juglans mandshurica Maxim using anti-hepatoma activity as a guide. Their structures were determined by comprehensive NMR and HRESIMS spectroscopic data analyses. All the isolated compounds were evaluated for their growth inhibitory activities against two kinds of liver cancer cell lines (HepG2 and Hep3B). Among them, compound 4 showed moderate cytotoxic activities against HepG2 and Hep3B cell lines with IC₅₀ values of 58.58 and 69.87 μM. Compound 5 exhibited 50% cell death rate in HepG2 and Hep3B cell lines at 63.70 and 46.45 μM, respectively. Further observation of morphological changes and Western blot demonstrated that compounds 4 and 5 exhibited their cytotoxic activities through the induction of apoptosis. A structure-activity relationship study suggested that an α, β-unsaturated aldehyde might be the most important functional group.     

Biochip detection of KRAS,BRAF, and PIK3CA somatic mutations in colorectal cancer patients

Molecular Biology - Somatic mutations of KRAS, PIK3CA, and BRAF cause insensitivity of colorectal tumors to therapy with anti-EGFR monoclonal antibodies, necessitating a genetic testing prior to...     

Piceatannol promotes apoptosis via up-regulation of microRNA-129 expression in colorectal cancer cell lines

Piceatannol, a naturally occurring analog of resveratrol, has been confirmed as an antitumor agent by inhibiting proliferation, migration, and metastasis in diverse cancer. However, the effect and mechanisms of piceatannol on colorectal cancer (CRC) have not been well understood. This study aimed to test whether piceatannol could inhibit growth of CRC cells and reveal its underlying molecular mechanism.     

Synthesis and biological evaluation of thienopyrimidine derivatives as GPR119 agonists

A series of thienopyrimidine derivatives was synthesized and evaluated for their GPR119 agonistic ability. Several thienopyrimidine derivatives containing R¹ and R² substituents displayed potent GPR119 agonistic activity. Among them, compound 5d, which is a prototype, showed good in vitro activity with an EC₅₀ value of 3 nM and human and rat liver microsomal stability. Compound 5d exhibited no CYP inhibition and induction, Herg binding, or mutagenic potential. Compound 5d showed increase insulin secretion in beta TC-6 cell and lowered the glucose excursion in mice in an oral glucose-tolerance test.     

Butyrate-induced apoptosis in HCT116 colorectal cancer cells includes induction of a cell stress response

Short chain fatty acids (SCFA), principally butyrate, propionate, and acetate, are produced in the gut through the fermentation of dietary fiber by the colonic microbiotica. Butyrate in particular is the preferred energy source for the cells in the colonic mucosa and has been demonstrated to induce apoptosis in colorectal cancer cell lines. We have used proteomics, specifically 2D-DIGE and mass spectrometry, to identify proteins involved in butyrate-induced apoptosis in HCT116 cells and also to identify proteins involved in the development of butyrate insensitivity in its derivative, the HCT116-BR cells. The HCT116-BR cell line was characterized as being less responsive to the apoptotic effects of butyrate in comparison to its parent cell line. Our analysis has revealed that butyrate likely induces a cellular stress response in HCT116 cells characterized by p38 MAPK activation and an endoplasmic reticulum (ER) stress response, resulting in caspase 3/7 activation and cell death. Adaptive cellular responses to stress-induced apoptosis in HCT116-BR cells may be responsible for the development of resistance to apoptosis in this cell line. We also report for the first time additional cellular processes altered by butyrate, such as heme biosynthesis and dysregulated expression of nuclear lamina proteins, which may be involved in the apoptotic response observed in these cell lines.     

Effects of rare earth compounds on growth and apoptosis of leukemic cell lines

To explore a new agent for inhibiting leukemic cells, we investigated the effects of rare earth compounds (lanthanum chloride and cerium chloride) on the growth and apoptosis of HL-60 and NB4 cells. The growth of HL-60 and NB4 cells was tested by 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) colorimetric assay. The apoptosis was measured by light microscopy, flow cytometry, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) method. The effect of LaCl(3) on normal bone marrow hematopoietic progenitor cells was evaluated by colony-forming unit-granulocyte-macrophage (CFU-GM) assay. Under our experimental conditions, MTT assay showed that 48-h treatment with 1, 2, and 3 mM LaCl(3) or 48- and 72-h treatments with 1 mM LaCl(3) could significantly inhibit the growth of HL-60 cells. Treatment with 2 and 4 mM CeCl(3) for 72 h could significantly inhibit the growth of NB4 cells. Apoptosis could be detected on treatment with 2 mM LaCl(3) for 24 h in HL-60 cells by light microscopic morphology examination, flow cytometric analysis, and TUNEL method. Apoptosis could be also detected on treatment with 2 mM CeCl(3) for 72 h in NB4 cells. Treatment with 1 mM LaCl(3) could arrest the transitions from G0/G1 to S phase. The granulocyte-macrophage colony formation of normal bone marrow cells was not significantly inhibited at lower concentrations of LaCl(3) (0.5 to 2 mM). Our results indicate that at certain concentrations, the rare earth compounds may inhibit the growth of leukemic cells, induce them to apoptosis, and have no significant inhibitory effects on normal bone marrow hematopoietic progenitor cells (CFU-GM). The mechanism needs to be further investigated.     

KRAS and BRAF mutation analysis can be reliably performed on aspirated cytological specimens of metastatic colorectal carcinoma

N. K. B. Pang, M. E. Nga, S. Y. Chin, T.‐M. Ismail, G. L. Lim, R. Soong and M. Salto‐Tellez
KRAS and BRAF mutation analysis can be reliably performed on aspirated cytological specimens of metastatic colorectal carcinoma Background: Sanger sequencing is one of several reliable methods in use to detect KRAS and BRAF mutations to facilitate clinical patient selection for anti‐epidermal growth factor receptor (EGFR) monoclonal antibody therapy in unresectable metastatic colorectal adenocarcinoma (CRC). Most analyses are made on pretreatment biopsy or resection specimens. There is a scarcity of published studies on the suitability of cytological samples for KRAS testing in this setting. Methods: DNA extraction was attempted on 11 search‐retrieved paired cases of histological resections or excisions of CRC and their corresponding cytological samples (representing metastases) and tested for KRAS mutations in exon 2 and 3, as well as BRAF exon 15 mutations by Sanger sequencing. Only KRAS wild‐type cases were subjected to BRAF analysis because this is the setting with true diagnostic value, as these mutations are mutually exclusive. Results: Of the 11 paired cases analysed, only eight histology cases showed satisfactory DNA quality for sequencing. Thus, only eight of the corresponding cytology cases were analysed. Seven of the eight cases tested showed the same KRAS genotype on both the aspirated cytology specimen of metastatic carcinoma and the primary tumour (histological specimen), from which we derive an overall concordance rate of 87.5%. The single discordant case was likely to be a true difference as it was demonstrated again on repeat testing of both samples. No BRAF mutations were detected on the four KRAS wild‐type cases. Conclusion: A range of cytological samples are suitable for KRAS and BRAF mutation testing, be it from previously stained preparations or cell blocks. These samples would be highly valuable in cases where cytological samples are the only material available for mutation testing.     

Synthesis of novel ciprofloxacin analogues and evaluation of their anti-proliferative effect on human cancer cell lines

A series of twenty two novel 1-cyclopropyl-6-fluoro-4-oxo-7-(4-substituted piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid analogues have been synthesized, characterized (¹H NMR, ¹³C NMR and LCMS) and evaluated for their inhibitory activity on the proliferation of human caucasian acute lymphoblastic leukemia cells (CCRF-CEM), breast adenocarcinoma cells (MDA-MB-468) and human colon carcinoma cells (HCT-116). Among all the synthesized ciprofloxacin analogues 3t at 50 μM showed comparable potency to doxorubicin (10 μM) in all three cell lines and 3j inhibited proliferation of MDA-MB-468 up to 35% selectively over other two cell lines.     

Oncogenic KRAS suppresses store-operated Ca2+ entry and ICRAC through ERK pathway-dependent remodelling of STIM expression in colorectal cancer cell lines

The KRAS GTPase plays a fundamental role in transducing signals from plasma membrane growth factor receptors to downstream signalling pathways controlling cell proliferation, survival and migration. Activating KRAS mutations are found in 20% of all cancers and in up to 40% of colorectal cancers, where they contribute to dysregulation of cell processes underlying oncogenic transformation. Multiple KRAS-regulated cell functions are also influenced by changes in intracellular Ca²⁺ levels that are concurrently modified by receptor signalling pathways. Suppression of intracellular Ca²⁺ release mechanisms can confer a survival advantage in cancer cells, and changes in Ca²⁺ entry across the plasma membrane modulate cell migration and proliferation. However, inconsistent remodelling of Ca²⁺ influx and its signalling role has been reported in studies of transformed cells. To isolate the interaction between altered Ca²⁺ handling and mutated KRAS in colorectal cancer, we have previously employed isogenic cell line pairs, differing by the presence of an oncogenic KRAS allele (encoding KRAS^G13D), and have shown that reduced Ca²⁺ release from the ER and mitochondrial Ca²⁺ uptake contributes to the survival advantage conferred by oncogenic KRAS. Here we show in the same cell lines, that Store-Operated Ca²⁺ Entry (SOCE) and its underlying current, I_CRAC are under the influence of KRAS^G13D. Specifically, deletion of the oncogenic KRAS allele resulted in enhanced STIM1 expression and greater Ca²⁺ influx. Consistent with the role of KRAS in the activation of the ERK pathway, MEK inhibition in cells with KRAS^G13D resulted in increased STIM1 expression. Further, ectopic expression of STIM1 in HCT 116 cells (which express KRAS^G13D) rescued SOCE, demonstrating a fundamental role of STIM1 in suppression of Ca²⁺ entry downstream of KRAS^G13D. These results add to the understanding of how ERK controls cancer cell physiology and highlight STIM1 as an important biomarker in cancerogenesis.     

Synthesis and cytotoxicity evaluation of glycosidic derivatives of lawsone against breast cancer cell lines

Breast cancer is the most incident and mortal cancer type in women, with an estimated 2 million new cases expected by 2020 worldwide, with 600,000 deaths. As not all breast cancer types respond to the anti-hormonal therapy, the development of new antineoplastic drugs is necessary. Lawsone (2-hydroxy-1,4-naphtoquinone) is a natural bioactive naphtoquinone displaying a range of activities, with dozens of derivatives described in the literature, including some glycosides possessing antitumor activity. Here, a series of glycosides of lawsone are reported for the first time and all compounds displayed good activity against the SKBR-3 cell line, with IC₅₀ below 10 µM. The most promising derivative was the glycosyl triazole derived from peracetylated d-glucose (11), which showed better cytotoxicity against SKBR-3 (IC₅₀ = 0.78 µM), being the most selective toward this tumoral cell (SI > 20). All compounds described in this work were more active than lawsone, indicating the importance of the carbohydrate and glycosyl triazole moiety for activity.     

TFF2 (trefoil family factor2) inhibits apoptosis in breast and colorectal cancer cell lines

We have recently demonstrated that human TFF2 inhibits apoptosis in the non-TFF2 expressing breast adenocarcinoma cell line MCF-7. In this study we examined the impact of TFF2 and an anti-TFF2 antibody (hSP3) on the survival of other human adenocarcinoma cell lines; TFF2-positive (LS174T and SW480) and TFF2-negative (MCF-7 and T47D). Addition of TFF2 protected the (TFF2-) lines but had no effect on those constitutively expressing TFF2. Blocking with hSP3 significantly increased apoptosis in the (TFF2+) cell lines with minimal effect on the (TFF2-) cells. Our results show that the cytoprotective effect of TFF2 seen in MCF-7 cells is not cell line-specific and can be abrogated by inhibition of its expression.     

Differential effects on growth, cell cycle arrest, and induction of apoptosis by resveratrol in human prostate cancer cell lines.

Epidemiologic studies have suggested that nutrition plays an important role in carcinogenesis and that 30% of cancer morbidity and mortality can potentially be prevented with proper adjustment of diets. Resveratrol, a polyphenol present in red wines and a variety of human foods, has recently been reported to exhibit chemopreventive properties when tested in a mouse skin cancer model system. In this study, we investigated the effects of resveratrol on growth, induction of apoptosis, and modulation of prostate-specific gene expression using cultured prostate cancer cells that mimic the initial (hormone-sensitive) and advanced (hormone-refractory) stages of prostate carcinoma. Androgen-responsive LNCaP and androgen-nonresponsive DU-145, PC-3, and JCA-1 human prostate cancer cells were cultured with different concentrations of resveratrol (2. 5 x 10(-5)-10(-7) M). Cell growth, cell cycle distribution, and apoptosis were determined. Addition of 2.5 x 10(-5) M resveratrol led to a substantial decrease in growth of LNCaP and in PC-3 and DU-145 cells, but only had a modest inhibitory effect on proliferation of JCA-1 cells. Flow cytometric analysis showed resveratrol to partially disrupt G1/S transition in all three androgen-nonresponsive cell lines, but had no effect in the androgen-responsive LNCaP cells. In difference to the androgen-nonresponsive prostate cancer cells however, resveratrol causes a significant percentage of LNCaP cells to undergo apoptosis and significantly lowers both intracellular and secreted prostate-specific antigen (PSA) levels without affecting the expression of the androgen receptor (AR). These results suggest that resveratrol negatively modulates prostate cancer cell growth, by affecting mitogenesis as well as inducing apoptosis, in a prostate cell-type-specific manner. Resveratrol also regulates PSA gene expression by an AR-independent mechanism.     

Trifluoromethylated carboline compounds targeting DNA: Synthesis,binding and anti-proliferative effects on human cancer cell lines

Three sets of carboline derived compounds were prepared by Pictet-Spengler cyclization. These tetrahydro β- and γ-carbolines have CF₃ group with an additional amino alkyl chains (α- or δ-position) and guanidine alkyl chains (α-position), of varying length. Structure–activity relationship of these molecules with calf thymus DNA was emphasized by fluorescence, ITC, FTIR and viscosity. Binding with DNA resulted in dramatic enhancement and quenching in the fluorescence emission. Gamma-carboline analogs showed maximum DNA binding followed by beta-carboline compounds with amino alkyl chain and least with guanidine alkyl chain compounds. It decreased with increasing chain length. The bindings were entropically driven being more with guanidine alkyl chain analogs. Site preference and mode of binding with partial intercalation and external binding was supported by FTIR and viscosity. Cytotoxic potencies of the compounds were tested on seven different cancer cell lines. The smallest alkyl chain analog attached to gamma position, Comp3, showed maximum cytotoxicity with GI₅₀ 6.2 µM, against HCT-116 causing apoptosis, followed by the guanidine alkyl chain compounds, but amino alkyl chain compounds to beta position showed poor cytotoxicity.These results may be of prospective use in a framework to design novel carboline derivatives as antitumor drugs for improved therapeutic applications in future.