Significance of the Ki-67 proliferation index in the assessment of the therapeutic response to cisplatin-based chemotherapy in patients with advanced cervical cancer.

OBJECTIVE: The purposes of this study were to examine the therapeutic response of advanced cervical cancer to Ki-67 proliferative index (Ki-67 PI) dependent cisplatin chemotherapy, and to determine Ki-67 PI referential value that is expected to provide a satisfactory therapeutic response of cervical cancer to cisplatin chemotherapy. PATIENTS AND METHODS: This prospective study enrolled 59 patients treated for cervical cancer at Clinic for Oncology, Clinical Center Nis, Serbia. According to the obtained Ki-67 PI values, patients were divided into three groups, and all the patients received the same cytostatic, cisplatin. Therapeutic response to chemotherapy was evaluated in relation to disease progression presence or absence and progression-free survival after a year follow-up since the first chemotherapy. RESULTS: Survival rate increases with an increase of Ki-67 PI by Kaplan-Meier survival analysis, meaning that survival rate is statistically significantly shorter in the group of patients with Ki-67 PI < 40% in comparison to patients from other two groups (p=0.010). Mann-Whitney test confirmed a statistically significant increase in survival rate among the groups of patients formed according to Ki-67 PI (p<0.05). Kaplan-Meier survival analysis confirmed that the mean survival rate in the group of patients with Ki-67 PI values over 60% is statistically significantly longer in comparison to patients with Ki-67 PI values below or equal 60% (p<0.001). CONCLUSIONS: Advanced cervical cancer with a high Ki-67 PI expression responds better to cisplatin-based chemotherapy, thus resulting in a longer survival rate. The values of Ki-67 PI were determined: high Ki-67 PI (≥ 60%), moderate Ki-67 PI (40-60%), and low Ki-67 PI (≤ 40%).

Crosstalk between possible cytostatic and antiinflammatory potential of ketoprofen in the treatment of culture of colon and cervix cancer cell lines.

OBJECTIVES: The aim of this study was to test the cytostatic potential of ketoprofen in the in vitro treatment of cells derived from colon and cervix cancer. BACKGROUND: NF-κB and cyclooxygenase can have a role in different stages of the development and progression of cancer. In recent years, special attention has been paid to the possible cytostatic potential of nonsteroidal anti-inflammatory drugs. There are no published data on the use of ketoprofen in pharmacotherapy of the colon and cervical carcinoma. METHODS: We examined the effect of ketoprofen alone or in combination with cisplatin and 5-fluorouracil on proliferation of the two cell lines, HeLa (human cervical carcinoma cells) and Caco-2 (human colon cancer cells) by MTT test. Measurement of the level of NF-κB was also performed in the cells of both cell lines. RESULTS: The results of present study have shown that at least one of the mechanisms of antiproliferating and/or cytostatic effects of different concentrations of ketoprofen on Caco-2 and HeLa cells could include the transcription factor NF-κB. CONCLUSIONS: Since this transcription factor is controlled by the altered expression of COX-2, the inhibition of this enzyme by ketoprofen may represent a significant step in synergistic cascade of the therapy and prevention of colon and cervical cancer (Tab. 4, Ref. 31).

Chemopreventive potential of alpha lipoic acid in the treatment of colon and cervix cancer cell lines.

OBJECTIVES: The nuclear factor κB regulates the expression of genes involved in many processes that play a key role in the development and progression of cancer. The aim of this study was to examine the influence of the alpha lipoic acid in the chemoprevention of colon and cervix carcinoma in vitro. BACKGROUND: In recent years, special attention has been paid to the potential chemopreventive properties of antioxidants. There are no published data on the impact of alpha lipoc acid of chemoprevention of cervix and colon cancer. METHODS: We examined the effect of alpha lipoic acid alone or in combination with cisplatin and 5-fluorouracil on proliferation of the two cell lines, HeLa (human cervical carcinoma cells) and Caco-2 (human colon cancer cells) by MTT test. The measurement of the level of transcription factor NF-κB was also performed in the cells of both cell lines. RESULTS: At least one of the mechanisms of the antiproliferative and/or cytotoxic effect of alpha lipoic acid on Caco-2 and HeLa cells at high concentrations, the transcription factor NF-κB, may be involved, as well as the products of transcription of genes that are under its control. CONCLUSION: The alpha lipoic acid has proven to be a promising candidate in the combat arena against cancer (Tab. 4, Ref. 31).

Functional characterization of the muscarinic receptors involved in endothelium-dependent relaxation in isolated canine uterine artery.

Acetylcholine interacts with endothelial muscarinic receptors releasing nitric oxide and causing vasodilatation. To identify the receptor subtype responsible for acetylcholine-induced relaxation in canine uterine artery, the usual organ bath method for in vitro investigation on isolated blood vessels was applied. Using a range of muscarinic receptor antagonists such as atropine (nonselective), pirenzepine (M(1)-selective), methoctramine (M(2)-selective) and p-fluoro-hexahydro-sila-difenidol (p-FHHSiD) (M(1)/M(3)) and determining pA2 value of those antagonists through Shild analysis, we aimed at establishing a precise receptor mechanism underlying acetylcholine-induced relaxation in isolated canine uterine artery. The relaxation of uterine arterial rings in response to acetylcholine in the presence or absence of selective muscarinic receptors antagonists was calculated using concentration response curves. Acetylcholine induced concentration-dependent and endothelium-dependent relaxation of arterial rings precontracted with phenylephrine (pEC(50) = 6.90 +/- 0.02). Muscarinic receptors antagonists atropine, pirenzepine, methoctramine and p-FHHSiD competitively antagonized the response to acetylcholine and obtained pA(2) values were 9.91 +/- 0.06, 6.60 +/- 0.04, 6.21 +/- 0.08 and 8.05 +/- 0.1, respectively. This study showed that acetylcholine induced endothelium-dependent relaxation of canine uterine artery by stimulation of muscarinic receptors localized on the endothelial cells. On the basis of differential antagonist affinity, we suggest that the muscarinic receptors involved in the acetylcholine-induced relaxation of canine uterine artery are predominantly of M(3) subtype.

Responses of the human submandibular artery to ACh and VIP.

Endothelial vasodilatory substances may play a central role in the local regulation of vascular tone. We hypothesized that these substances can mediate endothelium-dependent vasodilatory responses to acetylcholine (ACh) and vasoactive intestinal peptide (VIP) in the human submandibular artery. We evaluated the contributions of endothelial vasodilatory substances to vessel relaxation in response to ACh and VIP, using different inhibitors of endothelial vasodilation, the nitric oxide synthase inhibitor, the cyclo-oxygenase inhibitor, indomethacin, the potassium channel blocker, and 4-aminopyridine. ACh and VIP caused an endothelium- and concentration-dependent relaxation in this artery. ACh relaxation was completely blocked after the concomitant addition of N(G)-nitro-L-arginine and indomethacin. The vasorelaxant effect of ACh was not influenced by 4-aminopyridine. VIP relaxation was almost completely abolished by 4-aminopyridine, and was partly inhibited by N(G)-nitro-L-arginine, but was not affected by indomethacin. Thus, in the human submandibular artery, ACh and VIP produced endothelium-dependent vasodilation with different underlying mechanisms: release of nitric oxide (NO) and cyclo-oxygenase products for ACh, and release of NO and endothelium-derived hyperpolarizing factor for VIP.

The relaxant effect of vasoactive intestinal polypeptide in the isolated canine uterine artery: the role of endothelium.

The purpose of this study was to examine the effect of vasoactive intestinal polypeptide (VIP) on the uterine artery obtained from non-pregnant dogs. VIP (3 x 10(-9)-3 x 10(-7) M) induced concentration-dependent relaxation in canine uterine arteries with intact endothelium, pre-contracted with 10(-5) M phenylephrine (pEC(50) = 7.52 +/- 0.02, maximal response was 82.19 +/- 2.15%, n = 36). The administration of the cyclooxygenase inhibitor indomethacin (10(-5) M) or 4-aminopyridine (4-AP), a blocker of potassium channels (10(-5) M), did not modify the relaxation induced by VIP. Contrary to this, N(G)-nitro-L-arginine (L-NOARG) (10(-5) M) inhibited relaxation is evoked by VIP. Indomethacin applied with L-NOARG did not provoke further inhibition of VIP-induced relaxation. In the presence of both L-NOARG and L-NOARG + indomethacin, 4-AP led to the further inhibition of VIP-induced relaxation of canine uterine artery. It is concluded that VIP induces endothelium-dependent relaxation of uterine arteries of non-pregnant dogs, which can be entirely explained by the production of nitric oxide (NO) from the endothelial cells. We proposed that when NO synthesis is inhibited, VIP induces further relaxation, independent of the edothelium-derived relaxing factors, probably through activation of K(+) channels.

Endothelium-dependent relaxation of canine uterine artery in response to acetylcholine: the possible involvement of alternative pathways.

The effect of acetylcholine on the isolated, pre-contracted, uterine artery of non-pregnant dog was investigated. Acetylcholine-induced concentration-dependent relaxation of isolated canine uterine artery with endothelium (pEC50 = 6.48 +/-0.01, n = 37) and was without effect on arterial segments denuded of endothelium. Indomethacin, 4-aminopyridine (10-5 m) and pre-contraction with K+-rich Krebs-Ringer bicarbonate solution had no effect on acetylcholine-induced relaxation. NG-nitro-l-arginine (l-NOARG) (10-5 m) inhibited relaxation evoked by acetylcholine. Indomethacin applied with l-NOARG led to further inhibition of acetylcholine-induced relaxation. In the presence of both l-NOARG and indomethacin, 4-aminopiridine did not provoke further inhibition of acetylcholine-induced relaxation of canine uterine artery. It is concluded that the acetylcholine-induced relaxation of canine uterine artery is probably mediated by endothelial production of nitric oxide (NO). However, if NO-synthase is inhibited, acetylcholine-induced vasorelaxation may be, in part, mediated through activation of cyclooxygenase pathway.

Acetylcholine-induced contractions in the perforating branch of the human internal mammary artery: protective role of the vascular endothelium.

The effect of acetylcholine (ACh) on the isolated, nonprecontracted perforating branch of the human internal mammary artery (HIMA) was investigated. ACh induced concentration-dependent contractions of nonprecontracted rings with denuded endothelium (pEC(50) = 6.72 +/- 0.02, E(max) = 88.8% of contractions induced by phenylephrine, 10(-5) mol/l) and was without effect on arterial segments with intact endothelium. An inhibitor of nitric oxide synthase, N(G)-monomethyl-L-arginine (L-NMMA), or indometacin, a cyclooxygenase inhibitor, had no effect on acetylcholine-induced contractions of rings of the perforating branch of HIMA with denuded endothelium (pEC(50) = 6.76 +/- 0.03 and 6.62 +/- 0.05, respectively). In the presence of indometacin, ACh did not evoke contractions of arterial segments with intact endothelium. In contrast, in the same type of preparations ACh induced contractions in the presence of L-NMMA (E(max) = 34%). The muscarinic receptor antagonists atropine (no selectivity), pirenzepine (M(1)), methoctramine (M(2)), and p-fluoro-hexahydro-sila-difenidol (M(1)/M(3)) competitively antagonized the response to ACh. The pA(2) values were 9.60 +/- 0.10, 6.99 +/- 0.02, 6.37 +/- 0.17, and 8.02 +/- 0.06, respectively. In conclusion, the results obtained indicate that secretion of nitric oxide from vascular endothelium may protect the perforating branch of HIMA against the contractile effects of ACh. On the basis of differential antagonist affinity, it can be suggested that the muscarinic receptors involved in the ACh-induced contractions of the isolated perforating branch of the HIMA are predominantly of the M(3) subtype.

Muscarinic receptor subtypes mediating vasorelaxation of the perforating branch of the human internal mammary artery.

The effect of acetylcholine (ACh) on the isolated perforating branch of the human internal mammary artery (HIMA) was investigated. ACh induced concentration- and endothelium-dependent relaxation of arterial rings precontracted with phenylephrine (pEC(50) = 6.93 +/- 0.01). The muscarinic receptor antagonist atropine (no selectivity), pirenzepine (M(1)), methoctramine (M(2)), and p-fluoro-hexahydro-siladifenidol (M(1)/M(3)) competitively antagonized the response to ACh. The pA(2) values were 9.81 +/- 0.15, 7.74 +/- 0.08, 6.27 +/- 0.08, and 7.88 +/- 0.04, respectively. In conclusion, this study has shown that ACh induced an endothelium-dependent relaxation of the perforating branch of the HIMA by stimulation of muscarinic receptors on the endothelial cells. On the basis of differential antagonist affinity, we suggest that the muscarinic receptors involved in the ACh-induced relaxation of the isolated perforating branch of HIMA are predominantly of M(1) subtype.

Endothelium-dependent relaxation in perforating branch of human internal mammary artery.

The purpose of the present study was to examine the effect of acetylcholine on perforating branch of the human internal mammary artery (HIMA). Acetylcholine (10(-9)-10(-5)M) induced concentration- and endothelium-dependent relaxation (pEC(50)=7.54+/-0.03, maximal response was 98+/-1.3%) of the precontracted arterial segments. Indomethacin, 4-aminopyridine (10(-5)M) and precontraction with K(+)-rich Krebs-Ringer-bicarbonate solution had no effect on acethylcholine-induced relaxation. N(G)-monomethyl-L-arginine (L-NMMA) (10(-5)M) inhibited relaxation evoked by acetylcholine. Indomethacin applied together with L-NMMA lead to further inhibition of acethylcholine-induced relaxation. Even in the presence of both L-NMMA and indomethacin, 4-aminopyridine had no provoked further inhibition of acetylcholine-induced relaxation of perforating branch of HIMA. It was concluded that the acethylcholine-induced relaxation of isolated perforating branch of HIMA is probably mediated via endothelial production of nitric oxide. However, when NO-synthase is inhibited, acetylcholine-induced vasorelaxation may be, in part, mediated through activation of cyclooxygenase pathway and consequent production and release of prostacyclin or some other cyclooxygenase products.

Characterization of adenosine action in isolated rat renal artery. Possible role of adenosine A(2A) receptors.

Adenosine (0.1-300 microM) induced concentration- and endothelium-dependent relaxation of rat renal artery (RRA). N(G)-Nitro-L-arginine (L-NOARG, 10 microM) significantly reduced adenosine-elicited dilatation, but not the application of indomethacin (10 microM), ouabain (100 microM) or tetraethylammonium (TEA, 500 microM). In the presence of high concentration of K(+) (100 mM) or glibenclamide (1 microM), adenosine-evoked relaxation was almost abolished. 8-(3-Chlorostyril)caffeine (CSC, 0.3-3 microM), a selective A(2A)-antagonist, significantly reduced adenosine-evoked dilatation in a concentration-dependent manner (pA(2)=7.29). Conversely, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10 nM), an A(1)-antagonist, did not alter adenosine-induced relaxation. These results indicate that adenosine produces endothelium-dependent relaxation of isolated RRA. Dilatation evoked by adenosine is mediated by predominant releasing of endothelium-derived hiperpolarizing factor (EDHF) and also in one part of nitric oxide (NO) from endothelial cells. The obtained results also suggest that RRA response to adenosine is most likely initiated by activation of endothelial adenosine A(2A) receptors.

Acetylcholine-induced contractions in the porcine internal mammary artery: possible role of muscarinic receptors.

The effect of acetylcholine on the isolated, non-precontracted, porcine internal mammary artery (IMA) was investigated. Acetylcholine induced concentration-dependent contractions of non-precontracted IMA rings with denuded endothelium (pEC50 = 5.80 +/- 0.04) and was without effect on arterial segments with intact endothelium. The muscarinic receptor antagonists atropine, pirenzepine, methoctramine and p-fluoro-hexahydro-sila-diphenidol (pFHHSiD) antagonized the response to acetylcholine. The constrained pA2 values were 10.14, 7.74, 7.34 and 10.5, respectively. It is concluded that acetylcholine induces concentration-dependent contractions of porcine internal mammary artery rings on basal tone and that this contractile effect is probably due to direct cholinergic stimulation of smooth muscle cells, maybe including activation of muscarinic M1 receptors.