Design, synthesis and biological evaluation of4-[imidazolylmethyl]-2-[4-methylsulfonyl phenyl]-quinoline derivatives as selective COX-2 inhibitors and in-vitro anti-breast cancer agents

A new group of 4-[Imidazolylmethyl] quinoline derivatives possessing a methylsulfonyl COX-2 pharmacophore at the para position of the C-2 phenyl ring were designed and synthesized as selective COX-2 inhibitors and in-vitro anti breast cancer agents. In-vitro COX-1 and COX-2 inhibition studies showed that all the compounds were potent and selective inhibitors of the COX-2 isozyme with IC[50] values in the potent range 0.063-0.090 microM, and COX-2 selectivity indexes in the 179.9 to 547.6 range. Molecular modeling studies indicated that the methylsulfonyl substituent can be inserted into the secondary pocket of COX-2 active site for interactions with Arg[513]. Cytotoxicity of quinolines 9a-e against human breast cancer MCF-7 and T47D cell lines were also evaluated. All the compounds 9a-e were more cytotoxic against MCF-7 cells in comparison with those of T47D which express aromatase mRNA less than MCF-7 cells. The data showed that the increase of lipophilic properties of substituents on the C-7 and C-8 quinoline ring increased their cytotoxicity on MCF-7cells and COX-2 inhibitory activity. Among the quinolines 9a-e, 4-[[1H-Imidazol-1-yl]methyl] 7,8,9,10-tetrahydro-2-[4-methylsulfonylphenyl]-benzo[h]quinoline [9d]was identified as the most potent and selective COX-2 inhibitor as well as the most cytotoxic agent against MCF-7 cells

Correlation between cigarette smoking and urine cotinine level in gastric cancer patients

Various substances in cigarette smoke including nicotine have been shown to promote/induce cancer cell proliferation. Since cotinine has a longer half life and stability in the blood, it has become the preferred biomarker for cigarette smoking exposure. Seventy-three gastric cancer patients were included in this study. The tumor tissues were stained with H and E for pathological evaluation. The cotinine levels were measured in urine using a competitive ELISA. Tumors were 90% adenocarcinoma with 63% intestinal and 37% diffuse subtypes. Tumors were poorly [45.2%] or moderately differentiated [41.1%] and localized mainly [77%] in the upper part of stomach. The levels of cotinine were significantly different between smoker [283.83 +/- 178.10 ng/mL] and non-smoker [39.28 +/- 113.34 ng/mL] groups [p < 0.001]. However, there is no-significant correlation between tumor characteristics and cotinine level in smoker patients. Cotinine level correlates with smoking in gastric patients, however, correlation with the tumor features has not been observed

Synthesis, evaluation of anticancer activity and QSAR study of heterocyclic esters of caffeic acid

Caffeic acid phenethyl ester [CAPE] suppresses the growth of transformed cells such as human breast cancer cells, hepatocarcinoma, myeloid leukemia, colorectal cancer cells, fibrosarcoma, glioma and melanoma. A group of heterocyclic esters of caffeic acid was synthesized using Mitsunobu reaction and the esters were subjected to further structural modification by electrooxidation of the catechol ring of caffeic acid esters in the presence of sodium benzenesulfinate and sodium toluensulfinate as nucleophiles. Both heterocyclic esters of caffeic acid and their arylsulfonyl derivatives were evaluated for their cytotoxic activity against HeLa, SK-OV-3, and HT-29 cancer cell lines. HeLa cells showed the highest sensitivity to the compounds and heterocyclic esters with no substituent on catechol ring showed better activity compared to their substituted counterparts. QSAR studies reemphasized the importance of molecular shape of the compounds for their cytotoxic activity

study of DNA methylation of bax gene promoter in breast and colorectal carcinoma cell lines

The Bcl-2 protein family members have known as essential controllers of mitochondrial pathway of apoptosis. Bax is a proapoptotic member of Bcl-2 protein family, which is well known to play crucial roles for apoptosis control. bax has been implicated as potential tumor suppressor in certain solid tumors such as breast and colorectal carcinoma. DNA methylation of promoter associated CpG islands has known as a common mechanism for gene inactivation in tumor cells. The Methylation Specific PCR [MSP] has used to find the methylation profile of the bax gene promoter CpG islands in colorectal and breast cancer cell lines. We have not detected any kind of "CpG islands hyper methylation" in promoter region of the bax gene in T47D, MCF7 [as ER positive], MDA-MB-231 and MDA-MB-468 [as ER negative] breast carcinoma-derived cell lines and colorectal cancer cell lines H29 and Caco II. It seems that CpG island methylation could not play the main role in down-regulation of bax gene in breast and colon cancers

Real-Time RT-PCR on SAG1 and BAG1 Gene Expression during Stage Conversion in Immunosuppressed Mice Infected with Toxoplasma gondii Tehran Strain

Toxoplasmic encephalitis is caused by reactivation of bradyzoites to rapidly dividing tachyzoites of the apicomplexan parasite Toxoplasma gondii in immunocompromised hosts. Diagnosis of this life-threatening disease is problematic, because it is difficult to discriminate between these 2 stages. Toxoplasma PCR assays using gDNA as a template have been unable to discriminate between an increase or decrease in SAG1 and BAG1 expression between the active tachyzoite stage and the latent bradyzoite stage. In the present study, real-time RT-PCR assay was used to detect the expression of bradyzoite (BAG1)- and tachyzoite-specific genes (SAG1) during bradyzoite/tachyzoite stage conversion in mice infected with T. gondii Tehran strain after dexamethasone sodium phosphate (DXM) administration. The conversion reaction was observed in the lungs and brain tissues of experimental mice, indicated by SAG1 expression at day 6 after DXM administration, and continued until day 14. Bradyzoites were also detected in both organs throughout the study; however, it decreased at day 14 significantly. It is suggested that during the reactivation period, bradyzoites not only escape from the cysts and reinvade neighboring cells as tachyzoites, but also converted to new bradyzoites. In summary, the real-time RT-PCR assay provided a reliable, fast, and quantitative way of detecting T. gondii reactivation in an animal model. Thus, this method may be useful for diagnosing stage conversion in clinical specimens of immunocompromised patients (HIV or transplant patients) for early identification of tachyzoite-bradyzoite stage conversion.

Lead exposure impairs NMDA agonist-induced no production in pyramidal hippocampal cells

Chronic exposure to Lead [Pb] affects neural functions in central nervous system [CNS] particularly the learning and memory. On the other hand, alteration of calcium level in the CNS results in activation of NOS where it is expected to increase nitric oxide level in hippocampus. In this study the role of Lead exposure in NMDA induced NO production in pyramidal hippocampal cells [CA1HP] was investigated. The NO level was determined by measurement of concentration of nitrite and nitrate as NO products using the metHb production at 401 nm. The ACBD [NMDA agonist]-induced NO level was almost reduced to the control level [2.5 nM] in the presence of 10 and 100 nM of Lead acetate. Lead acetate at concentrations which normally results in chronic toxicity did not increase the nitric oxide [NO] production by CA1HP. One reason for this finding could be the interaction of Lead with NMDA receptors due to similarity of Pb[2+] to Zn[2+] ion. Another reason may be related to direct interaction of Lead with NMDA receptors that inhibit the stimulated NO production

Establishment of a doxorubicin-Resistant subline from acute myeloid leukemia cell line

In order to determine the multidrug resistance [MDR] phenotype due to P-glycoprotein expression in haematological malignancies including acute myeloblastic leukemia [AML], a well-characterized P-gp expressing cell line was required to validate and standardize flow cytometric assays and to calibrate instruments. Therefore, this resistant subline of K562 was established for the first time in Iran in order to study the MDR phenotype due to P-gp expression in some cancers. A resistant subline of K562 [KDI/20] to Doxorubicin from the same parental K562 was derived by stepwise increasing the concentration of Doxorubicin up to 20 ng/ml as a gold standard. For flow cytometric assessment of P-gp expression, 4E3 anti-P-gp was used. The resistant cell line was studied by rhodamine 123 for functional assay of P-gp. MDR1 gene expression was also confirmed using RT-PCR. P-glycoprotein was expressed in final concentration of 20 ng/ml of Doxorubicin on 70% of K562 cells after 120 passages. The Rhodamine 123 influx was 37%. The over-expression of MDR1 gene was observed in a 30-cycle PCR. P-glycoprotein is expressed in human K562 cell line [K562] by continuous exposure to anticancer drug. P-glycoprotein expression is detected by several methods including flow cytometry and RT-PCR, and the number of PCR cycles is very important

Cross-resistance to vincristin and etoposide in a sub line of the human breast cancer T47D cells selected for adriamycin-resistance

Breast cancer is one of the most common malignancies among women. Although chemotherapy remains a major therapeutic approach to treat cancers, drug therapy often fails for several reasons, particularly the drug resistance. Resistance to multiple chemotherapeutic agents is one of the most important problems in the treatment of different types of cancers. Therefore, in this study a resistant sub line of the human breast cancer T47D cells was isolated in vitro by stepwise exposure to increasing concentrations of Adriamycin [ADR] to compare the characteristics of parent and resistant cells. We also evaluated the phenomenon of cross-resistance to some other chemotherapeutic drugs. A significant increase in doubling time of resistant cells, named T47D/ADR, [94 h] was observed when compared to the parental T47D cells [50 h] that indicates a relatively slow growth rate pattern of these cells. T47D/ADR cells were 4 fold resistant to adriamycin and also showed cross-resistance to vincristin [VCR, 3.5 fold] and to etoposide [VP-16, 5.5 fold] when compared to parent cells. Therefore, our results indicate that T47D/ADR cells are also cross-resistant to structurally and functionally different chemotherapeutic agents and can be used as a model for studying molecular changes of drug resistance