Anthracyclines in non-small cell lung cancer

Silver(I), Zinc(II) and Gallium(III) thiophene-2-carboxylates: Synthesis, solution and solid state characterization and bioevaluation

Three 2-thiophenecarboxylate (Tio2c) complexes with different central atoms Ag(I), Zn(II) and Ga(III), [Ag(Tio2c)]2 (AgTio2c), {[Zn2(Tio2c)4]2}n (ZnTio2c) and [Ga(Tio2c)3]·H2O (GaTio2c), were synthesized and elemental, spectral and thermal analyses were used for their characterization. The AgTio2c and ZnTio2c single crystal structures confirmed the most common bidentate bridging coordination mode with typical strong argentophilic interactions in the case of AgTio2c complex. Complexes' stability in biological test stock solution were confirmed by 1H NMR spectroscopy. Potentiometric data analysis by BSTAC program resulted in the determination of the stability constants of four complex species, [Zn(Tio2c)]+ (log β110 = 2.06 ± 0.04), [Zn(Tio2c)(OH)] (log β11-1 = -5.0 ± 0.1), [Zn(Tio2c)(OH)2]- (log β11-2 = -12.9 ± 0.4) and [Zn(Tio2c)2(OH)2]2- (log β12-2 = -8.54 ± 0.04) with low abundance in aqueous solution. Theoretical estimation of the complex species in aqueous solution indicates a rather monodentate Tio2c coordination mode in the [Zn(Tio2c)]+ species, while the hydroxido complex species prefer a rather bidentate O,O'-bond of the carboxylate. Antimicrobial and anticancer bioassays clearly confirmed the highest biological activity (toxicity) of the AgTio2c complex. The activity of ZnTio2c was slightly higher (or the same) compared to GaTio2c. The HSA (human serum albumin) binding behaviour of the AgTio2c, ZnTio2c and GaTio2c complexes was investigated using fluorescence spectroscopy and results revealed that the calculated Kb values were in the order of 104 M-1.

Acridine Based N-Acylhydrazone Derivatives as Potential Anticancer Agents: Synthesis, Characterization and ctDNA/HSA Spectroscopic Binding Properties

A series of novel acridine N-acylhydrazone derivatives have been synthesized as potential topoisomerase I/II inhibitors, and their binding (calf thymus DNA—ctDNA and human serum albumin—HSA) and biological activities as potential anticancer agents on proliferation of A549 and CCD-18Co have been evaluated. The acridine-DNA complex 3b (-F) displayed the highest Kb value (Kb = 3.18 × 103 M−1). The HSA-derivatives interactions were studied by fluorescence quenching spectra. This method was used for the calculation of characteristic binding parameters. In the presence of warfarin, the binding constant values were found to decrease (KSV = 2.26 M−1, Kb = 2.54 M−1), suggesting that derivative 3a could bind to HSA at Sudlow site I. The effect of tested derivatives on metabolic activity of A549 cells evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay decreased as follows 3b(-F) > 3a(-H) > 3c(-Cl) > 3d(-Br). The derivatives 3c and 3d in vitro act as potential dual inhibitors of hTopo I and II with a partial effect on the metabolic activity of cancer cells A594. The acridine-benzohydrazides 3a and 3c reduced the clonogenic ability of A549 cells by 72% or 74%, respectively. The general results of the study suggest that the novel compounds show potential for future development as anticancer agents.

Epigenetics and miRNA as predictive markers and targets for lung cancer chemotherapy

Lung cancer cells show inherent and acquired resistance to chemotherapy. The lack of good predictive markers/novel targets and the incomplete understanding of the mechanisms of resistance limit the success of lung cancer response to chemotherapy. In the present study, we used an isogenic pair of lung adenocarcinoma cell lines; A549 (wild-type) and A549DOX11 (doxorubicin resistant) to study the role of epigenetics and miRNA in resistance/response of non-small cell lung cancer (NSCLC) cells to doxorubicin. Our results demonstrate differential expression of epigenetic markers whereby the level of HDACs 1, 2, 3 and4, DNA methyltransferase, acetylated H2B and acetylated H3 were lower in A549DOX11 compared to A549 cells. Fourteen miRNAs were dys-regulated in A549DOX11 cells compared to A549 cells, of these 14 miRNAs, 4 (has-mir-1973, 494, 4286 and 29b-3p) have shown 2.99 - 4.44 fold increase in their expression. This was associated with reduced apoptosis and higher resistance of A549DOX11cells to doxorubicin and etoposide. Sequential treatment with the epigenetic modifiers trichostatin A or 5-aza-2'-deoxycytidine followed by doxorubicin resulted in: (i) enhanced sensitivity of both cell lines to doxorubicin especially at low concentrations, (ii) enhanced doxorubicin-induced DNA damage in both cell lines, (iii) dysregulation of some miRNAs in A549 cells. In conclusion, A549DOX11 cells resistant to DNA damaging drugs have epigenetic profile and miRNA expression different from the sensitive cells. Moreover, epigenetic modifiers may reverse the resistance of certain NSCLC cells to DNA damaging agents by enhancing induction of DNA damage. This may open the door for using epigenetic profile/miRNA expression of some cancer cells as resistance markers/targets to improve response of resistant cells to doxorubicin and for the use of combination doxorubicin/epigenetic modifiers to reduce doxorubicin toxicity.

Induced Resistance in the Human Non Small Cell Lung Carcinoma (NCI-H460) Cell Line In Vitro by Anticancer Drugs

Exposure of human non-small cell lung cancer cells (NCI-H460) to gradually increasing concentrations of doxorubicin resulted in the appearance of a new cell line (NCI-H460/R) that was resistant to doxorubicin (96.2-fold) and cross-resistant to etoposide, paclitaxel, vinblastine and epirubicin. Slight cross-resistance to two MDR-unrelated drugs 8-Cl-cAMP and sulfinosine was observed. Flow cytometry analysis showed that the accumulation of doxorubicin in the resistant cells was 88.4% lower than in the parental cells. Also, verapamil significantly decreased the efflux rate in NCI-H460 and NCI-H460/R cells, whereas curcumin inhibited the efflux in NCI-H460 cells only. Gene expression data confirmed the induction of mdr1 (P-gp), as judged by the observed 15-fold increase in its mRNA concentration in doxorubicin-resistant NCI-H460/R cells. In contrast, mrp1 and lrp expression was unaffected by the doxorubicin resistance. Further work should develop a rationale for a novel treatment of NSCLC with appropriate modulators of resistance aimed at improving the outcome of the acquired drug resistance.

Features of senescence and cell death induced by doxorubicin in A549 cells: organization and level of selected cytoskeletal proteins

PURPOSE

Senescence and cell death are fail-safe mechanisms protecting against tumorigenesis. Both these forms of cellular response could be induced in cancer cells, thus suppressing tumor progression. Therefore, to fully understand chemotherapeutic effects, not only symptoms of cell death, but also of senescence should be evaluated. Since the involvement of cytoskeleton components in these processes has been reported, changes in the organization and level of some cytoskeletal proteins may be indicative of cell fate.

METHODS

We analyzed selected markers of senescence and cell death, including possible alterations in vimentin and G-actin cytoskeleton in A549 cells after treatment with doxorubicin. Light (SA-beta-galactosidase), fluorescent (vimentin and G-actin labeling) and electron microscopic examinations along with flow cytometry methods (TUNEL, Annexin V/PI staining, cell cycle analysis, intracellular level of vimentin) were employed to determine the outcome of the treatment.

RESULTS

Uncoupling between senescent cell morphology and stable cell cycle arrest occurred. Some differences in the organization and level of cytoskeletal proteins, especially of vimentin, like fluctuations in its level, were observed. On the other hand, G-actin seemed to be more stable than vimentin.

CONCLUSIONS

G-actin stability may imply its potential usefulness for permanent senescence detection. Along with slight to moderate cytoskeletal alterations, the obtained results suggest transient senescence-like state induction, followed by morphology typical of mitotic catastrophe in part of the A549 cells.

Gemcitabine plus conventional-dose epirubicin versus gemcitabine plus cisplatin as first-line chemotherapy for stage IIIB/IV non-small cell lung carcinoma--a randomized phase II trial

BACKGROUND

Epirubicin was effective for the treatment of non-small cell lung carcinoma (NSCLC). This study compared the efficacy and safety of gemcitabine plus conventional-dose epirubicin (GE) with gemcitabine-cisplatin (GC) as first-line chemotherapy for stage IIIB/IV NSCLC and evaluated the predictive value of nuclear expression of excision repair cross-complementing group 1 (ERCC1) and topoisomerase IIalpha (TopoIIalpha) on treatment outcome.

PATIENTS AND METHODS

Patients were randomized to GE (gemcitabine, 1000mg/m(2) on days 1, 8, and 15 and epirubicin, 70mg/m(2) on day 15) or GC (gemcitabine, 1000mg/m(2) on days 1, 8, and 15 and cisplatin, 80mg/m(2) on day 15). Treatment cycles were repeated every 4 weeks. Immunohistochemical study of ERCC1 and TopoIIalpha was done for patients with available tumor specimens.

RESULTS

The response rate was 31.0% (95% CI 16.4-45.5%) for GC (n=41) and 37.2.0% (95% CI 22.2-52.3%) for GE (n=39). No significant differences in median time-to-treatment-failure (TTF) (GC, 6.1 months; GE, 6.2 months) or overall survival (GC, 13.2 months; GE, 21.5 months) were found between the two arms. Grade 3/4 neutropenia and febrile neutropenia were more common in GE. However, delay of protocol treatment due to leukopenia was similar between the two arms. Patients with expression of both ERCC1 and TopoIIalpha had a significantly shorter TTF (median 2.4 months, 95% CI 0.7-4.1 months) than other patients (median 8.8 months, 95% CI 5.8-11.8 months) (p=0.04).

CONCLUSION

GE regimen is effective and well-tolerated for NSCLC patients. Expression of both ERCC1 and TopoIIalpha may be associated with poor response to chemotherapy.

Oral silibinin inhibits lung tumor growth in athymic nude mice and forms a novel chemocombination with doxorubicin targeting nuclear factor kappaB-mediated inducible chemoresistance

The acute and cumulative dose-related toxicity and drug resistance, mediated via nuclear factor kappaB (NFkappaB), of anthracycline anticancer drugs pose a major problem in cancer chemotherapy. Here, we report that oral silibinin (a flavanone) suppresses human non-small-cell lung carcinoma A549 xenograft growth (P = 0.003) and enhances the therapeutic response (P < 0.05) of doxorubicin in athymic BALB/c nu/nu mice together with a strong prevention of doxorubicin-caused adverse health effects. Immunohistochemical analyses of tumors showed that silibinin and doxorubicin decrease (P < 0.001) proliferation index and vasculature and increase (P < 0.001) apoptosis; these effects were further enhanced (P < 0.001) in combination treatment. Pharmacologic dose of silibinin (60 mumol/L) achieved in animal study was biologically effective (P < 0.01 to 0.001, growth inhibition and apoptosis) in vitro in A549 cell culture together with an increased efficacy (P < 0.05 to 0.001) in doxorubicin (25 nmol/L) combination. Furthermore, doxorubicin increased NFkappaB DNA binding activity as one of the possible mechanisms for chemoresistance in A549 cells, which was inhibited by silibinin in combination treatment. Consistent with this, silibinin inhibited doxorubicin-caused increased translocation of p65 and p50 from cytosol to nucleus. Silibinin also inhibited cyclooxygenase-2, an NFkappaB target, in doxorubicin combination. These findings suggest that silibinin inhibits in vivo lung tumor growth and reduces systemic toxicity of doxorubicin with an enhanced therapeutic efficacy most likely via an inhibition of doxorubicin-induced chemoresistance involving NFkappaB signaling.

The role of new agents in the treatment of non-small cell lung cancer

Lung cancer is one of the most frequent causes of cancer deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for approximately 80% of cases and no curative treatment is available for the advanced stages of disease (stages III and IV), which comprise the majority of cases. Current treatment regimens with standard chemotherapy offer only a limited survival benefit, and, therefore, the development of new therapeutic strategies is needed. Novel chemotherapeutic drugs such as the epothilones, MEN 10755 and S-1 are being studied in patients with advanced stages of disease. Furthermore, a large number of therapies targeted against critical biological abnormalities in NSCLC are being investigated in clinical trials. The latter approach includes inhibition of growth factors, interference with abnormal signal transduction, inhibition of angiogenesis and gene replacement therapy. Promising results have thus far been obtained with some of these therapies. This review describes the role of new therapeutic agents in the treatment of NSCLC.