Synergistic effect of pyrrolidine dithiocarbamate and cisplatin in human cervical carcinoma

We aimed to delineate how pyrrolidine dithiocarbamate (PDTC) affects nuclear factor κB (NF-κB) and to determine its antitumor activity alone and in combination with cisplatin in human cervical cancer SiHa cells. The SiHa cells were treated with various concentrations of PDTC and/or cisplatin at various time intervals. Cell proliferation and apoptosis were determined using a water-soluble tetrazolium salt 8 assay and flow cytometry. Electrophoretic mobility shift assay was used to assess NF-κB activity. Pyrrolidine dithiocarbamate (2.5-100 µmol/L) was found to inhibit the growth of SiHa cell lines. Cisplatin (0.01-20.0 μg/mL) and PDTC (2.5-20.0 µmol/L) combined demonstrated additive inhibitive effects on cell growth and increased the level of apoptosis. In addition, PDTC blocked cisplatin-induced activation of NF-κB, leading to enhanced apoptosis and increased chemosensitivity to cisplatin. Taken together, PDTC has significant potential as a chemotherapy agent, alone or in combination with cisplatin.

Role of gefitinib in patients with recurrent or metastatic cervical carcinoma ineligible or refractory to systemic chemotherapy: first study from Asia

OBJECTIVES

There are limited options for patients with recurrent or metastatic cervical carcinoma who are either refractory to or ineligible for systemic chemotherapy. We conducted a clinical study to evaluate the role of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in such patients.

METHODS

Eligible patients were enrolled into the study and were treated with gefitinib at a dose of 250 mg/day orally until disease progression, development of intolerable adverse effects, or withdrawal of consent. The primary end point of the study was progression-free survival. The secondary end points were stable disease, overall survival, and toxicity.

RESULTS

From January 2008 to June 2011, a total of 20 patients were enrolled. Median age was 52 years and median disease-free interval was 15 months. Twelve patients presented with locoregional recurrence, 2 patients presented with distant metastases, and 6 patients presented with both locoregional recurrence and distant metastasis. Median duration of gefitinib therapy was 4 months. One patient had complete response, 1 patient had partial response, 4 patients had stable disease, and 14 patients had progressive disease. The median progression-free survival and overall survival were 4 months and 5 months, respectively. Only 1 patient had severe drug-related toxicity.

CONCLUSIONS

Gefitinib is safe and seems to be effective in recurrent or metastatic cervical carcinoma. Further studies are warranted to identify the subgroup of patients, based on epidermal growth factor receptor mutations, who are more likely to benefit.

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening.

Novel approaches for concurrent irradiation in locally advanced cervical cancer: platinum combinations, non-platinum-containing regimens, and molecular targeted agents

Despite the available prevention and early detection strategies, squamous-cell carcinoma of the uterine cervix is still diagnosed as locally advanced disease in a considerable proportion of patients. As a potent sensitizer of cancer cells, cisplatin has been the "traditional partner" of external beam irradiation in this setting for more than two decades. Induction chemotherapy strategies followed by concurrent chemoradiation or surgery and preoperative concurrent chemoradiation have been recently implemented in clinical trials in an effort to optimize local control and to minimize the risk of distant metastases. In this context, cisplatin has been combined with a number of other potential radiosensitizers, including 5-fluorouracil, capecitabine, and gemcitabine. In patients resistant or intolerant to platinum compounds, numerous non-platinum-containing regimens have been developed, implementing various antimetabolites, taxanes, antineoplastic antibiotics, and topoisomerase II inhibitors. More recently, molecular agents targeting critical pathways in cervical malignant transformation are being assessed in early clinical trials in combination with external-beam irradiation. In the current work, we review the evolving role of cisplatin and other platinum compounds, either alone or in combination regimens, in the context of other potent radiosensitizers. The emerging role of molecular targeted agents, as candidate partners of external beam irradiation, is also discussed.

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.

Hedgehog pathway regulators influence cervical cancer cell proliferation, survival and migration

Human papillomavirus (HPV) infection is considered to be a primary hit that causes cervical cancer. However, infection with this agent, although needed, is not sufficient for a cancer to develop. Additional cellular changes are required to complement the action of HPV, but the precise nature of these changes is not clear. Here, we studied the function of the Hedgehog (Hh) signaling pathway in cervical cancer. The Hh pathway can have a role in a number of cancers, including those of liver, lung and digestive tract. We found that components of the Hh pathway are expressed in several cervical cancer cell lines, indicating that there could exists an autocrine Hh signaling loop in these cells. Inhibition of Hh signaling reduces proliferation and survival of the cervical cancer cells and induces their apoptosis as seen by the up-regulation of the pro-apoptotic protein cleaved caspase 3. Our results indicate that Hh signaling is not induced directly by HPV-encoded proteins but rather that Hh-activating mutations are selected in cells initially immortalized by HPV. Sonic Hedgehog (Shh) ligand induces proliferation and promotes migration of the cervical cancer cells studied. Together, these results indicate pro-survival and protective roles of an activated Hh signaling pathway in cervical cancer-derived cells, and suggest that inhibition of this pathway may be a therapeutic option in fighting cervical cancer.

Epidermal growth factor receptor as a biomarker for cervical cancer

This review focuses on the different modes of expression of the epidermal growth factor receptor (EGFR). All methods used to assess EGFR expression are critically analyzed and insights into the use of inhibitors of EGFR for treatment of cervical cancer are discussed. Currently, expression of EGFR as a biomarker for prognosis or for treatment of cervical cancer is not defined for clinical use.

Locally advanced cervical cancer: what is the standard of care?

PURPOSE OF REVIEW

Carcinoma of the cervix remains a significant health problem for women worldwide. Locally advanced cervical cancer (LACC) is a common presentation that has been extensively studied in the last three decades. This article reviews the standard of care and discusses current topics of clinical research.

RECENT FINDINGS

A multidisciplinary approach to the treatment of cervical cancer has led to marked improvement in outcome. Main advances are with neoadjuvant chemotherapy, chemoradiation, and preventive vaccination. Concurrent chemoradiation with a platinum-based agent is the recommended treatment for LACC. Palliation with platinum agent remains the standard of care for inoperable patients who have metastatic or recurrent disease.

SUMMARY

This is a review of published and ongoing studies testing multidisciplinary and medical management of LACC, with a focus on newer chemotherapeutic approaches. Optimal multidisciplinary treatment planning improves the outcome of each patient diagnosed with cervical cancer.

Pharmacotherapy of cervical cancer

IMPORTANCE OF THE FIELD

Cervical cancer (CC) remains an important health problem. It is the second most frequent malignancy in women worldwide, with one-third of patients dying from pharmacoresistant disease.

AREAS COVERED IN THIS REVIEW

We reviewed pharmacotherapy approaches in the medical and multidisciplinary management of CC and conducted a systematic search of Pubmed for clinical trials, reviews and meta-analysis published in the last 20 years. Abstracts of the American Society of Clinical Oncology, European Society of Gynecological Oncology and International Gynecologic Cancer Society were also searched, together with the US National Institutes of Health clinical trial database.

WHAT THE READER WILL GAIN

The state-of-the art of cytotoxic and biologically targeted therapies in early, locally advanced and metastatic/recurrent CC is discussed.

TAKE HOME MESSAGE

Until recently, the role of pharmacotherapy in CC was restricted to palliation of advanced/metastatic or recurrent disease. During the past two decades, this reluctant attitude towards chemotherapy has been modified after a series of randomized trials demonstrated its beneficial contribution as an adjunct to radiotherapy or surgery in early and locally advanced CC. Moreover, new combinations of cytotoxics, together with novel molecular target agents, open new perspectives in the treatment of primary and recurrent CC.