New drugs in the treatment of recurrent or metastatic cervical cancer

Four electrode-based impedimetric biosensors for evaluating cytotoxicity of tamoxifen on cervical cancer cells

In the current study, novel four electrode-based impedimetric biosensors have been fabricated using photolithography techniques and utilized to evaluate the cytotoxicity of tamoxifen on cervical cancer cell lines. The cell impedance was measured employing the electric cell-substrate impedance sensing (ECIS) method over the frequency range of 100 Hz to 1 MHz. The results obtained from impedimetric biosensors indicate that tamoxifen caused a significant reduction in the number of HeLa cells on the electrode surfaces in a dose-dependent manner. Next, the impedance values recorded by the fabricated biosensors have been compared with the results obtained from the different conventional techniques such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), live-dead cell assay, and flow cytometric analysis to estimate the cytotoxicity of tamoxifen. The impedimetric cytotoxicity of tamoxifen over the growth and proliferation of HeLa cells correlates well with the traditional methods. In addition, the IC50 values obtained from impedimetric data and MTT assay are comparable, signifying that the ECIS technique can be an alternative method to assess the cytotoxicity of different novel drugs. The working principle of the biosensor has been examined by scanning electron microscopy, indicating the detachment of cells from gold surfaces in a dose-dependent manner, signifying the decrease in impedance at higher drug doses.

Vaginal Suppositories with siRNA and Paclitaxel-Incorporated Solid Lipid Nanoparticles for Cervical Cancer: Preparation and In Vitro Evaluation

The objective of this study is to prepare vaginal suppository containing chemotherapeutic agent and genetic material that can be applied locally for cervical cancer. Cervical cancer is one of the most life-threatening types of cancer among women and is generally resistant to chemotherapy. Paclitaxel has been selected as chemotherapeutic agent, and siRNA that inhibits the Bcl-2 oncogene has been selected as the genetic material for simultaneous vaginal delivery. For this purpose, three different solid lipid nanoparticles (SLNs) were prepared that include Bcl-2 siRNA and paclitaxel and paclitaxel/Bcl-2 siRNA combination separately, and these SLN formulations were dispersed in vaginal suppositories prepared with PEG 6000. First, the physicochemical properties of SLNs, their cytotoxicities on HeLa cell lines, and the transfection ability of siRNA-incorporated SLN on the cells have been examined. Afterward, the release of SLNs from the three different vaginal suppositories prepared has been determined via horizontal diffusion chamber system. The loaded amount to the SLNs and release amount from suppositories of paclitaxel have been determined via HPLC, whereas stability, loading, and release amount of siRNA has been determined via gel retardation system and UV spectrophotometer.

Preparation and in vitro evaluation of vaginal formulations including siRNA and paclitaxel-loaded SLNs for cervical cancer

Cervical cancer is one of the most life threatening types of cancer among women and is generally resistant to chemotherapy. The objective of this study was to prepare a vaginal suppository containing a chemotherapeutic agent and a genetic material that can be applied locally for cervical cancer. Paclitaxel was selected as the chemotherapeutic agent and siRNA which inhibits BCL-2 oncogene was selected as the genetic material. Bcl-2 siRNA, paclitaxel and paclitaxel/Bcl-2 siRNA combination were incorporated into solid lipid nanoparticles (SLNs) and were dispersed separately in vaginal suppositories prepared with PEG 6000. Physicochemical properties of SLNs, their cytotoxicities on HeLa cell lines and also the effect of SLNs on the total protein amount of the cells were examined followed by the investigation of release rates of the active materials from the SLNs prepared. Average diameters of all SLNs prepared were below 180nm with a positive zeta potential value between +22.20 and +48.16mV at the pH range of 4.2 and 7.4. The release of Bcl-2 siRNA from SLNs incorporated Bcl-2 siRNA and the release of paclitaxel (PTX) from PTX incorporated SLNs were completed within 12h and 36h. SLNs incorporating Bcl-2 siRNA and paclitaxel/Bcl-2 siRNA were found to be more toxic when compared to paclitaxel incorporated SLN and placebo SLN. The disintegration of the vaginal suppositories as well as the release of the SLNs was completed within 2 h. This study indicates that vaginal suppository containing SLNs can bring the advantages of the simultaneous delivery of paclitaxel and siRNA via vaginal route with no help from professionals.

State-of-the-Art Treatment and Novel Agents in Local and Distant Recurrences of Cervical Cancer

Depending on the stage at initial presentation, cervical cancer will recur in 25-61% of women. Typical manifestations of recurrent cervical cancer include the central pelvis and the pelvic side walls as well as retroperitoneal lymph node basins in the pelvis and the para-aortic region, and - more rarely - supraclavicular lymph nodes. There are no typical symptoms of recurrent cervical cancer. Women with suspected recurrence after cervical cancer based on gynecological examination or organ-specific symptoms must undergo imaging studies and - if technically feasible - biopsy with histological verification, especially in cases of distant metastases, in order to rule out a second primary. Radiotherapy-naïve women should be treated with salvage radiochemotherapy with curative intention. For women with previous radiotherapy, surgery in the form of hysterectomy, local resection, or pelvic exenteration is the treatment of choice. Pelvic exenteration can lead to cure in selected patients, but at the price of a high rate of complications and significant morbidity and mortality. If complete surgical resection is not feasible or if the woman is not a candidate for surgery, chemotherapy with palliative intent should be offered. Patients with recurrent disease outside the pelvis are candidates for systemic chemotherapy. Several agents have shown to be active in this situation, either in single-agent or combination regimens. Platinum-containing regimens have a superior efficacy over non-platinum regimens and bevacizumab may be added to chemotherapy.

Enhanced killing of cervical cancer cells by combinations of methyl jasmonate with cisplatin, X or alpha radiation

Current therapies for treatment of advanced cervical cancer involve the use of cisplatin, often in combination with radiotherapy. These treatments do not lead to a high survival rate and furthermore, serious side effects are dose-limiting factors. Methyl jasmonate (MJ) was recently identified as potent and selective cytotoxic agent towards cervical cancer cells. In the present study we evaluated the effectiveness of combined treatments of MJ with cisplatin or X-irradiation on a variety of cervical cancer cells including SiHa, CaSki, HeLa and C33A. Cytotoxicity of alpha particles, emitted from (224)Ra atoms, was also evaluated as a single agent and in combination with MJ. Cooperation between MJ and cisplatin in reducing cell viability (XTT assays) and survival (clonogenicity assays) was exhibited towards several cancer cell lines at a range of combination doses. MJ effectively cooperated also with X-ray irradiation, significantly lowering the radiation doses required to inhibit cell survival (ID50) of all tested cells lines. We show for the first time, that alpha irradiation selectively reduced cell viability and survival of cervical cancer cells. Lower doses of α irradiation were required as compared to X-irradiation to inhibit cell survival. Cooperation with MJ was demonstrated in part of the cancer cell lines. In conclusion, our studies point to α irradiation and MJ, novel anticancer agents, as potent candidates for treatment of cervical cancer, in single agent regiments and in combination. MJ can be added also to conventional X-ray and cisplatin therapies to increase their cytotoxic effect while lowering the effective dose.

Methyl jasmonate reduces the survival of cervical cancer cells and downregulates HPV E6 and E7, and survivin

The present study further investigated the mode of action of methyl jasmonate (MJ) in different cervical cancer cell lines. We show that in addition to the short term cytotoxicity, MJ effectively reduced the survival of cervical cancer cells (clonogenicity assays). MJ induced apoptosis in all cervical cancer cells. In some cell lines, MJ caused elevation of the mitochondrial superoxide anion, notably, in HeLa and CaSki. Changes in the expression of p53 and bax were variable, yet, downregulation of survivin was common to all cervical cancer cells. MJ significantly reduced the levels of the human papillomavirus (HPV) E6 and E7 proteins without alteration of the mRNA levels. Moreover, ectopic expression of E6, E7 or both in cervical cancer cells that lack HPV (C33A), did not alter significantly their response to MJ. Our studies point to MJ as an effective anticancer agent against a variety of cervical cancer cells acting through shared and different pathways to induce cell death regardless of the presence of HPV.

Addition of gemcitabine to standard therapy in locally advanced cervical cancer: A randomized comparative study

BACKGROUND

The concurrent chemoradiotherapy for cervical cancer treatment is well accepted since 1999. This randomized, phase III trial aimed to observe if any improved outcome could be obtained capitalizing on the synergistic activity of gemcitabine, cisplatin, XRT.

MATERIALS AND METHODS

Stage IIB-IIIB, 18-70 years of age, KPS score ≥70, were randomized to control group and study group. Control group received cisplatin 40 mg/m(2) weekly with concurrent XRT, followed by brachytherapy and study group received gemcitabine 125 mg/m(2) weekly top of the same control group treatment. The primary end point was pathological response and toxicities along with patient compliance to treatment, late reactions, DFS and OS. Fifty patients were randomized between two arms.

RESULTS

The complete response in study and control arm was 96% and 88% respectively. Toxicities was significantly high in the study group compared to control group [leucopenia (P=0.015), skin reaction (P=0.03) and bleeding (P=0.019)]. Local recurrence rate: 8% in study arm, none in control arm. The distant failure prevailed in control arm (20% vs. 8%). On a median follow up of 21 months in control arm, the DFS was 73% whereas 83% in study arm in 16 months (P=0.69). OS in the study arm was 100% and 84.5% in the control arm (P=0.14).

CONCLUSIONS

If the toxicity can be managed adequately in the combination chemo radiation group, it may produce an improvement in response. Survival benefit can also be obtained by introducing gemcitabine to cisplatin as radio sensitizer.

Anticancer and cytotoxic effects of a triorganotin compound with 2-mercapto-nicotinic acid in malignant cell lines and tumor bearing Wistar rats

Nowadays, investigation for possible therapeutic applications of various metal-based drugs attracts the scientific interest worldwide. The triorganotin compound bis[triphenyltin(IV)](3-carboxy-pyridine-2-thionato) (SnMNA), was tested for its anti-proliferative and antitumor activities. Cytotoxic activity was assessed by Trypan blue and 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide assay (MTT). SnMNA exhibited potent cytotoxic effects against leiomyosarcoma cells (LMS) and human breast adenocarcinoma cells (MCF-7), which is 200 times stronger than that of cisplatin. Moreover, SnMNA induced significant apoptosis in LMS and MCF-7 cells characterized by flow cytometry analysis and DNA fragmentation. Acute and chronic toxicity studies on Wistar rats caused kidney and lung toxicity at a single dose of 80mg/kgBody Weight (BW) or four repeated doses of 8mg/kgBW once per week. Furthermore, antitumor activity studies on sarcoma bearing Wistar rats revealed that SnMNA complex at four repeated doses of 5.4mg/kgBW every three days prolonged mean survival time of the animal at 200% and decreased mean tumor growth rate (MTGR) compared to the control group (p<0.05). It is noteworthy to mention that the 30% (3 out of 10) of the bearing animals were totally cured. These findings indicate that SnMNA might be a promising new antitumor agent.

Methyl jasmonate induces cell death with mixed characteristics of apoptosis and necrosis in cervical cancer cells

In the present study the effectiveness of methyl jasmonate (MJ) against cervical cancer cell lines was investigated. We show that MJ is cytotoxic to a range of cervical cancer lines including SiHa, CaSki and HeLa that carry human papillomavirus (HPV) DNA and wild type p53, and C33A that is negative for HPV and contains mutant p53. Primary human foreskin keratinocytes were almost resistant to the drug. Cytotoxicity of MJ was dose and time dependent, and associated mainly with the induction of cell death and to a less extent with inhibition of cell growth. Cell death induced by MJ displayed features characteristic to both apoptosis and necrosis, and was associated with different changes in the levels of p53, p21, bcl-2 and bax in the various cervical cancer lines. In conclusion, MJ a novel anticancer agent, acts via multiple pathways to induce death of cervical cancer cells, thus making it a promising candidate for treatment of cervical cancer.

The tumor specific cytotoxicity of dihydronitidine from Toddalia asiatica Lam

PURPOSE

In recent years, a number of reports have shown the anticancer activity of plant extracts and phytoalkaloid.

METHODS

We have evaluated the cytotoxicity profiles of 157 extracts prepared from dietary or medical plants growing in the Okinawa island, using 10 different cell lines. In vitro cytotoxicity screening indicated the presence of a highly selective cytotoxic compound in the extract of Toddalia asiatica Lam. The known alkaloid (1,3)benzodioxolo(5,6-c)phenanthridine, 12,13-dihydro-2,3-dimethoxy-12-methyl-(dihydronitidine) was identified as an active material from this plant. This alkaloid had highly specific cytotoxicity to human lung adenocarcinoma (A549) cells.

RESULTS

The results of the fluorescence activated cell sorter (FACS) analysis and the measurement of caspase-3 activity showed that dihydronitidine induced specific apoptotic cell death in A549 cells. Gene expression analysis in the apoptotic cells found that dihydronitidine variously regulated the cell cycle related genes (CDK2 and CCNE), and up-regulated the cell death related genes specifically in tumor cells. Thus dihydronitidine manifested its characteristics in the tumor selective cytotoxicity, contrasting with the case of a known anticancer agent camptothecin (CPT). Microscopic observation further revealed the specific accumulation of dihydronitidine within the cytosolic organelle, but not in the nuclei of adenocarcinoma. No accumulation was observed with CPT in all cell lines.

CONCLUSION

The data suggested that dihydronitidine toxicity targeted a particular intracellular organelle in the tumor cells.

Clinical aspects and prognosis of pelvic recurrence of cervical carcinoma

OBJECTIVE

To identify which patients with locally recurrent cervical carcinoma are potentially curable.

METHOD

A total of 664 stage IB-IVA patients were examined following surgery or radiotherapy.

RESULT

Among the 664 patients, 193 (29%) developed recurrence. Sixty-seven (35%) of these recurrences were located in the pelvis alone. Among these 67 recurrences, 24 (35%) were central recurrences and the remaining 43 (65%) were pelvic side-wall recurrences. Of the 24 patients with central recurrences, 8 were salvaged. Of these 8 patients, 3 underwent pelvic exenteration, and 5 received optimal radiotherapy. The recurrent tumor in these 5 survivors who received radiotherapy had consisted of a small (<2 cm) tumor. All 43 patients with pelvic wall recurrence developed progressive disease.

CONCLUSION

The following patients are potentially curable: patients with a resectable, centrally located tumor who are candidates for pelvic exenteration, and patients with a small central recurrence for whom complete radiation therapy is feasible.

p53-Dependent Apoptotic Mechanism of a New Designer Bimetallic Compound Tri-phenyl Tin Benzimidazolethiol Copper Chloride (TPT-CuCl2): In Vivo Studies in Wistar Rats as Well as in Vitro Studies in Human Cervical Cancer Cells

We have studied the effect of tri-phenyl tin benzimadazolethiolcopper chloride (TPT-CuCl(2)), a novel bimetallic compound, on the regulation of apoptosis in HeLa cells, MCF-7 cells, and in vivo Wistar rat model. TPT-CuCl(2) induces significant apoptosis in HeLa cell line characterized by DNA fragmentation and chromosome condensation. Comet assay revealed that TPT-CuCl(2) targets and causes severe damage to the DNA. Treatment of HeLa cells with TPT-CuCl(2) rescues the accumulation of p53 from the suppression of human papilloma virus E6, resulting in a dramatic up-regulation of Bax and Bak and down-regulation of the antiapoptotic factor Survivin. Apoptotic induction by TPT-CuCl(2) was shown to mediate in a p53-depedent manner; loss of p53 impairs the release of cytochrome c and Smac/DIABLO from mitochondria to cytosol. Moreover, we have shown that TPT-CuCl(2) induced-apoptosis was through an intrinsic mitochondrial pathway, which was inhibited by viral oncoprotein E1B19K. Caspase-3 was found to be indispensable in TPT-CuCl(2)-triggered apoptosis signaling pathway, because caspase-3 deficient cell line MCF-7 was resistant to TPT-CuCl(2). Furthermore, in vivo studies using C6 glioblastoma xenograft rat model revealed that TPT-CuCl(2) exhibits significant antiproliferative activity against tumor development with minimal cytotoxicity toward normal physiological function of the experimental rats. These findings imply the attractiveness of TPT-CuCl(2) as a drug candidate for further development.