Topotecan in the management of cervical cancer

Co-administration of Chrysin and Luteolin with Cisplatin and Topotecan Exhibits a Variable Therapeutic Value in Human Cancer Cells, HeLa

Combinational treatment is a promising strategy for better cancer treatment outcomes. Chrysin and luteolin have demonstrated effective anticancer activity. Cisplatin and topotecan are commonly used for the treatment of human cancers. However, various side effects including drug resistance are an imperative restriction to use them as pharmacological therapy. Therefore, the aim was to use these agents in combination with flavones for better efficacy. In the present study, it was found that the combination of chrysin and cisplatin and luteolin and cisplatin significantly improved the anticancer effect as both the combinations showed synergistic interactions [combinational index (CI < 1)]. Remarkably, the combination of chrysin and luteolin with topotecan depicted the antagonistic interaction (CI > 1). Further, increased expression of the pro-apoptotic proteins Bax and caspase 8 and the inhibition of the antiapoptotic protein Bcl-2 were instituted in the synergistic doses (chrysin + cisplatin and luteolin + cisplatin), hence promoting apoptosis. Also, it was found that the synergistic combination inhibited the migration of HeLa cells by downregulation of metalloproteases and upregulation of TIMPs. However, there are no significant changes depicted in the antagonistic combinations which support their role in their antagonistic effects. Based on these results, it can be inferred that the two or more drug combinations need to be explored well for their interaction to enhance the therapeutic outcomes.

A Recent Advancement in Nanotechnology Approaches for the Treatment of Cervical Cancer

BACKGROUND

Cervical cancer is one of the leading causes of female death, with a mortality rate of over 200,000 per year in developing countries. Despite a decrease in cervical cancer occurrences in developed countries over the last decade, the frequency of the disease in developing nations continues to rise at an alarming rate, particularly when it is linked to the human papillomavirus (HPV). With just a few highly invasive conventional therapies available, there is a clear need for novel treatment options such as nanotechnology-based chemotherapeutic drug delivery.

METHODS

Traditional anticancer therapy is limited by poor drug potency, non-specificity, unwanted side effects, and the development of multiple drug resistance (MDR), leading to a decrease in long-term anticancer therapeutic efficacy. An ideal cancer therapy requires a personalized and specialized medication delivery method capable of eradicating even the last cancer cell responsible for disease recurrence.

RESULTS

Nanotechnology provides effective drug delivery mechanisms, allowing it to serve both therapeutic and diagnostic purposes. Nanotechnology-based formulations are widely used to accurately target the target organ, maintain drug load bioactivity, preferentially accumulate the drug at the target location, and reduce cytotoxicity.

CONCLUSION

The key benefits of this drug delivery are that it improves pharmacological activity, solubility, and bioavailability and reduces toxicity in the target tissue by targeting ligands, allowing for new innovative treatment methods in an area that is desperately required. The goal of this review is to highlight possible research on nanotechnologybased delivery systems for cancer detection and treatment.

Molecular relation between biological stress and carcinogenesis

This paper aims to overview different types of stress, including DNA replication stress, oxidative stress, and psychological stress. Understanding the processes that constitute a cellular response to varied types of stress lets us find differences in how normal cells and cancer cells react to the appearance of a particular kind of stressor. The revealed dissimilarities are the key for targeting new molecules and signaling pathways in anticancer treatment. For this reason, molecular mechanisms that underlay DNA replication stress, oxidative stress, and psychological stress have been studied and briefly presented to indicate biochemical points that make stressors contribute to cancer development. What is more, the viewpoint in which cancer constitutes the outcome and the cause of stress has been taken into consideration. In a described way, this paper draws attention to the problem of cancer-related post-traumatic stress disorder and proposes a novel, multidimensional oncological approach, connecting anticancer treatment with psychiatric support.

A novel microfluidic liposomal formulation for the delivery of the SN-38 camptothecin: characterization and in vitro assessment of its cytotoxic effect on two tumor cell lines

PURPOSE

Irinotecan (CPT-11) and SN-38 - its active metabolite - are alkaloid-derived topoisomerase I interactive compounds widely used in various cancer therapy protocols. To solve the problems associated with the instability of their lactone ring at physiological pH and with the extreme insolubility of SN-38, the development of delivery carriers (eg, liposomes) has been considered a subject of unquestionable medical interest. This article focuses on the development of an alternative protocol to the classical lipid-film hydration procedures to obtain a pharmaceutical formulation for SN-38.

METHODS

SN-38-loaded liposomes (SN-38lip) were produced by microemulsification, without a prior lipid-film preparation step, and characterized by different methods. Formulation parameters were determined by photon correlation spectroscopy, and the SN-38 entrapment efficiency was evaluated by absorbance spectroscopy. SN-38lip was obtained as a dry, white powder by lyophilization. MTT and LDH assays were conducted to assess the cytotoxic effect of SN-38, both in liposomal (SN-38lip) and solubilized form (SN-38sol); flow cytometry was used to quantify SN-38 uptake and to analyze cell-cycle phase distribution after drug exposure.

RESULTS

Microfluidic, stable, and controlled sized, negatively charged liposomes, with high SN-38 incorporation efficiency into egg yolk phosphatidylcholine (EPC)/L-α-dioleoyl-phospathidylserine (DOPS) (9:1) vesicles (SN-38lip), were prepared. A lyophilized powder of SN-38lip, easily reconstitutable while retaining physicochemical parameters, was finally obtained. The efficacy of SN-38lip was assessed by in vitro studies with two tumor cell lines (HeLa and Caco-2) and compared with that of SN-38sol. It demonstrated the highest uptake of SN-38lip, in accordance with its highest cytotoxicity effect, in comparison with that of SN-38sol. In addition, different cell-cycle alterations were induced in both cell lines by the liposomal formulation.

CONCLUSION

The results highlight the potential usefulness of the procured SN-38 liposomal formulation and provide the basis for conducting in vivo studies that allow the development of alternative strategies for colorectal cancer treatment.

Drug-induced hepatotoxicity in cancer patients - implication for treatment

INTRODUCTION

All anticancer drugs can cause idiosyncratic liver injury. Therefore, hepatoprotective agents assume particular importance to preserve liver function. Hepatic injury represents 10% of cases of acute hepatitis in adults; drug-related damage is still misjudged because of relative clinical underestimation and difficult differential diagnosis. Chemotherapeutic agents can produce liver toxicity through different pathways, resulting in different categories of liver injuries, but these drugs are not homogeneously hepatotoxic. Frequently, anticancer-induced hepatotoxicity is idiosyncratic and influenced by multiple factors.

AREAS COVERED

The aim of this paper is to perform a review of the literature regarding anticancer-induced liver toxicity. We described hepatotoxicity mechanisms of principal anticancer agents and respective dose reductions. Furthermore, we reviewed studies on hepatoprotectors and their optimal use. Tiopronin, magnesium isoglycyrrhizinate and S-Adenosylmethionine (AdoMet) demonstrated, in some small studies, a potential hepatoprotective activity.

EXPERT OPINION

Actually, in the literature only small experiences are reported. Even though hepatoprotective agents seem to be useful in the oncologic setting, the lack of well-designed prospective Phase III randomized controlled trials is a major limit in the introduction of hepatoprotectors in cancer patients and these kind of studies are warranted to support their use and to give further recommendations for the clinical practice.

Liposomal topotecan formulation with a low polyethylene glycol grafting density: pharmacokinetics and antitumour activity

Objectives

PEGylated liposomes could evade recognition by the reticulo-endothelial system and prolong the circulation time of vesicles, resulting in enhanced targeting efficiency and antitumour effect. Typically, vesicles are modified with distearoylphosphatidylethanolamine (DSPE)-polyethylene glycol (PEG) at a high PEG grafting density. However, long circulation time and slow drug release rate might induce severe hand-foot syndrome in clinical practice. In this study, a liposomal topotecan formulation with a low PEG grafting density was prepared and its pharmacokinetics, acute toxicity and antitumour effect were investigated.

Methods

Topotecan was loaded into liposomes using an ammonium sulfate gradient. The resulting formulation was injected to healthy Wistar rats at different dose levels to investigate whether its clearance followed linear kinetics. Biodistribution was performed in Lewis lung cancer-bearing mice. The acute toxicity was evaluated in healthy mice and beagle dogs. To compare the antitumour effects of different formulations and dose schedule, RM-1 prostate, Lewis lung, H446 and L1210 cancer models were used.

Key findings

Topotecan could be encapsulated into low DSPE-PEG liposomes with ∼100% loading efficiency. The clearance of the liposomal formulation followed linear kinetics at a dose level ranging from 0.5 to 4 mg/kg despite the fact that the vesicles were coated at a low PEG density. Compared with free topotecan the liposomal formulation preferentially accumulated into tumour zones instead of normal tissues. Both formulations could rapidly accumulate into liver and tumour, but the liposomal formulation was cleared from tissues at a slow rate relative to the conventional formulation. In rats and beagle dogs, liposomal formulations could not induce skin toxicity. In all the tumour models, smaller split doses were more therapeutically active than larger doses when the overall dose intensity was equivalent.

Conclusions

This has been the first report that plasma kinetics of a liposomal formulation with a low PEG density followed linear kinetics. Moreover, due to its short circulation half-life, the formulation did not induce skin toxicity. Our data revealed that the dose schedule of liposomal drugs should be adjusted in accordance with the biophysical and biological properties of the formulations to achieve the optimal therapeutic efficacy.

Outcomes of advanced and recurrent cervical cancer treated with cisplatin and generic topotecan: retrospective analysis in a tertiary care hospital in Thailand

OBJECTIVE

Retrospective evaluation of the outcome of stage IVB, recurrent or persistent cervical cancer treated with cisplatin and generic topotecan (CT) in a tertiary care hospital in Thailand.

METHODS

The medical records of patients treated with CT regimen at Chiang Mai University Hospital between January 2005 and December 2007 were reviewed and analyzed. The treatment protocol consisted of IV topotecan 0.75 mg/m(2) on days 1, 2, and 3; combined with cisplatin 50 mg/m(2) IV on day 1 and repeated every 21 days until progression or unacceptable toxicity for a maximum of 6 cycles. The outcomes were evaluated based on the response rate, progression free survival (PFS), and overall survival (OS) by using the World Health Organization criteria. The adverse effects of the treatments were also determined.

RESULTS

Twenty-one cervical cancer patients received the CT regimen. The tumor response rate was 28.6%. The median PFS and OS was 4 and 11 months, respectively. With 87 cycles of chemotherapy, the most common grade 3 & 4 hematologic toxicity was neutropenia (57.9%).

CONCLUSION

Advanced and recurrent cervical cancer patients treated with cisplatin and generic topotecan had a favorable outcome with manageable toxicity.

Review role of topotecan in gynaecological cancers: current indications and perspectives

BACKGROUND

Ovarian cancer is the fourth cause of death from gynaecological cancer and cervical cancer is the first in women <45 years old in developing countries. The aim of this article is to review the role of topotecan (Hycamtin), a semi-synthetic alkaloid derivative of camptothecin, in ovarian and cervical cancer in monotherapy and in combination.

METHODS

This article reviews the mechanism of action, pharmacokinetics, toxicity and efficacy of topotecan. The paper also reports the principal phases II and III studies of topotecan in advanced or recurrent ovarian and cervical cancer.

RESULTS

Topotecan (Hycamtin), currently indicated for the treatment of relapsed ovarian cancer, has demonstrated activity both in platinum-sensitive and in platinum-resistant disease. The combination cisplatin-topotecan for the treatment of advanced and recurrent cervical cancer has demonstrated a clinical benefit in terms of response rate, overall survival and progression free survival. Haematological toxicity of topotecan also is easy to manage and not cumulative, especially with the weekly scheduled recently introduced in clinical practice.

CONCLUSION

Topotecan (Hycamtin) will continue to play a role in the treatment of advanced ovarian and cervical cancer, in monotherapy or in combination with other cytotoxic agents.

ISG15 as a novel tumor biomarker for drug sensitivity

Tumor cells are known to exhibit highly varied sensitivity to camptothecins (CPT; e.g., irinotecan and topotecan). However, the factors that determine CPT sensitivity/resistance are largely unknown. Recent studies have shown that the ubiquitin-like protein, IFN-stimulated gene 15 (ISG15), which is highly elevated in many human cancers and tumor cell lines, antagonizes the ubiquitin/proteasome pathway. In the present study, we show that ISG15 is a determinant for CPT sensitivity/resistance possibly through its effect on proteasome-mediated repair of topoisomerase I (TOP1)-DNA covalent complexes. First, short hairpin RNA-mediated knockdown of either ISG15 or UbcH8 (major E2 for ISG15) in breast cancer ZR-75-1 cells decreased CPT sensitivity, suggesting that ISG15 overexpression in tumors could be a factor affecting intrinsic CPT sensitivity in tumor cells. Second, the level of ISG15 was found to be significantly reduced in several tumor cells selected for resistance to CPT, suggesting that altered ISG15 regulation could be a significant determinant for acquired CPT resistance. Parallel to reduced CPT sensitivity, short hairpin RNA-mediated knockdown of either ISG15 or UbcH8 in ZR-75-1 cells resulted in increased proteasomal degradation of CPT-induced TOP1-DNA covalent complexes. Taken together, these results suggest that ISG15, which interferes with proteasome-mediated repair of TOP1-DNA covalent complexes, is a potential tumor biomarker for CPT sensitivity.

A review of topotecan in combination chemotherapy for advanced cervical cancer

Treatment of advanced, recurrent or persistent cervical cancer includes radiotherapy and chemotherapy. Radiation has been the primary treatment modality for locoregionally advanced cervical cancer. Concomitant systemic cisplatin chemotherapy and radiation have shown high response rates with improvements in durable remissions and overall survival. Cisplatin has been the standard medication for the treatment of advanced cervical cancer. Combinations with other chemotherapeutic agents have been the subject of clinical trials with varying results. The toxicity of combination chemotherapy and tolerability of patients are other factors that should be considered in the management of patients with advanced disease. Recently topotecan, in combination with cisplatin, achieved increased response and overall survival rates without further compromising the patients' quality of life. This review focuses on the mechanism of action and toxicities of topotecan, as well as its role as a radio-sensitizer and chemotherapeutic agent in the management of advanced, recurrent, or persistent cervical cancer. Other combination modalities and dosages are also discussed.