First-line chemotherapy with 5-FU and platinum for advanced and recurrent cancer of the cervix: a phase II study

Targeted drug delivery in cervical cancer: Current perspectives

Cervical cancer is preventable yet one of the most prevalent cancers among women around the globe. Though regular screening has resulted in the decline in incidence, the disease claims a high number of lives every year, especially in the developing countries. Owing to rather aggressive and non-specific nature of the conventional chemotherapeutics, there is a growing need for newer treatment modalities. The advent of nanotechnology has assisted in this through the use of nanocarriers for targeted drug delivery. A number of nanocarriers are continuously being developed and studied for their application in drug delivery. The present review summarises the different drug delivery approaches and nanocarriers that can be useful, their advantages and limitation.

Overview of Evidence-Based Chemotherapy for Oral Cancer: Focus on Drug Resistance Related to the Epithelial-Mesenchymal Transition

The increasing incidence of resistance to chemotherapeutic agents has become a major issue in the treatment of oral cancer (OC). Epithelial-mesenchymal transition (EMT) has attracted a great deal of attention in recent years with regard to its relation to the mechanism of chemotherapy drug resistance. EMT-activating transcription factors (EMT-ATFs), such as Snail, TWIST, and ZEB, can activate several different molecular pathways, e.g., PI3K/AKT, NF-κB, and TGF-β. In contrast, the activated oncological signal pathways provide reciprocal feedback that affects the expression of EMT-ATFs, resulting in a peritumoral extracellular environment conducive to cancer cell survival and evasion of the immune system, leading to resistance to multiple chemotherapeutic agents. We present an overview of evidence-based chemotherapy for OC treatment based on the National Comprehensive Cancer Network (NCCN) Chemotherapy Order Templates. We focus on the molecular pathways involved in drug resistance related to the EMT and highlight the signal pathways and transcription factors that may be important for EMT-regulated drug resistance. Rapid progress in antitumor regimens, together with the application of powerful techniques such as high-throughput screening and microRNA technology, will facilitate the development of therapeutic strategies to augment chemotherapy.

A robust photoluminescence screening assay identifies uracil-DNA glycosylase inhibitors against prostate cancer

Many cancers have developed resistance to 5-FU, due to removal by the enzyme uracil-DNA glycosylase (UDG), a type of base excision repair enzyme (BER) that can excise uracil and 5-fluorouracil (5-FU) from DNA. However, the development of UDG inhibitor screening methods, especially for the rapid and efficient screening of natural product/natural product-like compounds, is still limited so far. We developed herein a robust time-resolved photoluminescence method for screening UDG inhibitors, which could significantly improve sensitivity over the screening method based on the conventional steady-state spectroscopy, reducing the substantial fluorescence background interference. As a proof-of-concept, two potential UDG inhibitors were identified from a database of natural products and approved drugs. Co-treatment of these two compounds with 5-FU showed synergistic cytotoxicity, providing the basis for treating drug-resistant cancers. Overall, this method provides an avenue for the rapid screening of small molecule regulators of other BER enzyme activities that can avoid false negatives arising from the background fluorescence.

The discovery of UDG inhibitors against prostate cancer by using a robust photoluminescence screening assay that can avoid false negatives arising from the background fluorescence.

In situ-forming and pH-responsive hydrogel based on chitosan for vaginal delivery of therapeutic agents

One of the important routes of drug administration for localized delivery of contraceptives and cervical cancer treatment agents is vaginal canal. Due to the low pH of vagina, a pH-responsive drug delivery system was developed. This hydrogel was synthesized based on a mucoadhesive biopolymer, chitosan (CS), that promotes the interaction between the hydrogel and mucosal surface of the vagina, potentially increasing the residence time of the system. This injectable hydrogel was formed via acid-labile Schiff-base linkages between free amine groups and aldehyde functionalities on modified chitosan. A novel approach was taken to add aldehyde functionalities to chitosan using a two-step reaction. Two types of slow and fast degrading hydrogels were prepared and loaded with iron (II) gluconate dihydrate, a non-hormonal spermicide, and doxorubicin hydrochloride, an anti-cancer drug. The release profiles of these drugs at different pH environments were assessed to determine the pH-dependent release mechanism. Mechanical properties, swell-ability and degradation rate of these matrices were studied. The cross-linking density of the hydrogel as well as pH changes played an important role in the characteristic of these hydrogels. The hydrogels degraded faster in lower pH, while the hydrogel with lower cross-linking density showed longer gelation time and faster degradation rate compared to the gel with higher cross-linking density. In vitro cytotoxicity assessment of these hydrogels in 48 h indicated the non-toxic effect of these hydrogels toward mesenchymal stem cells (MSCs) in the test period.

Chromatin tandem affinity purification sequencing

Chromatin immunoprecipitation coupled with ultra-high-throughput sequencing (ChIP-seq) is a widely used method for mapping the interactions of proteins with DNA. However, the requirements for ChIP-grade antibodies impede wider application of this method, and variations in results can be high owing to differences in affinity and cross-reactivity of antibodies. Therefore, we developed chromatin tandem affinity purification (ChTAP) as an effective alternative to ChIP. Through the use of affinity tags and reagents that are identical for all proteins investigated, ChTAP enables one to directly compare the binding between different transcription factors and to directly assess the background in control experiments. Thus, ChTAP-seq can be used to rapidly map the genome-wide binding of multiple DNA-binding proteins in a wide range of cell types. ChTAP can be completed in 3-4 d, starting from cross-linking of chromatin to purification of ChIP DNA.

Carboplatin and paclitaxel for advanced and recurrent cervical carcinoma: the British Columbia Cancer Agency experience

BACKGROUND

One of the most active chemotherapy combinations in advanced or recurrent cervical cancer is cisplatin-paclitaxel. However, this palliative regimen is associated with significant toxicity. Carboplatin-paclitaxel is thus an attractive option.

METHODS

Patients with advanced or recurrent carcinoma of the cervix treated with carboplatin-paclitaxel from April 2000 were included in the study. Starting doses of carboplatin-paclitaxel were: AUC 5-6 and 155-175 mg/m(2), respectively, repeated every 28 days.

RESULTS

Twenty-five women treated with this combination were identified. Twenty-three women (92%) had prior treatment with pelvic radiotherapy and 14 (56%) had had concurrent radio-sensitizing cisplatin. There was a 20% PR and a 20% CR rate (10/25). The median progression-free survival for the entire group was 3 months. Responders had a median PFS of 16 months. Fourteen patients (56%) had died of disease progression. The median overall survival (OS) was 21 months. Common toxicities included: grade 1 or 2 anemia, 68%; grade 3 or 4 anemia, 32%; grade 3 or 4 neutropenia, 32%; and grade 1 or 2 peripheral neuropathy, 24%. ECOG PS did not change significantly while on treatment. Eighty-four percent of treatments were delivered on time, and 96% at full dose.

CONCLUSIONS

Carboplatin-paclitaxel is an active combination in advanced and recurrent cervical cancer. In this predominantly pre-irradiated group, the combination was deliverable, well tolerated, and the most commonly observed toxicity was anemia.