Phase-I study of sagopilone in combination with cisplatin in chemotherapy-naive patients with metastasised small-cell lung cancer

Anti-tubulin agents of natural origin: Targeting taxol, vinca, and colchicine binding domains

Microtubules are a protein which is made of α- and β-heterodimer. It is one of the main components of the cell which play a vital role in cell division especially in G2/M-phase. It exists in equilibrium dynamic of polymerization and depolymerization of α- and β-heterodimer. It is one of the best targets for developing anti-cancer drugs. Various natural occurring molecules are well known for their anti-tubulin effect such as vinca, paclitaxel, combretastatin, colchicine etc. These microtubule-targeted drugs are acted through two processes (i) inhibiting depolymerization of tubulin (tubulin stabilizing agents) and (ii) inhibiting polymerization of tubulin (tubulin destabilizing agents). Now days, various binding domains have been explore through which these molecules are binding to tubulin but the three major binding domain of tubulin are taxol, vinca and colchicine binding domain. The present article mainly focus on the classification of various naturally occurring compounds on the basis of their inhibition processes (depolymerization and polymerization) and the site of interaction (targets taxol, vinca and colchicine binding domain) which has been hitherto reported. By placing all the naturally occurring taxol, vinca and colchicine binding site analogues at one place makes a better understanding of the tubulin interactions with known natural tubulin binders that would helps in the discovery of new and potent natural, semi-synthetic and synthetic analogues for treating cancer.

A regulatory circuit composed of DNA methyltransferases and receptor tyrosine kinases controls lung cancer cell aggressiveness

Overexpression of DNMT1 and KIT is prevalent in lung cancer, yet the underlying molecular mechanisms are poorly understood. While the deregulated activation of DNMT1 or KIT has been implicated in lung cancer pathogenesis, whether and how DNMT1 and KIT orchestrate lung tumorigenesis are unclear. Here, using human lung cancer tissue microarrays and fresh frozen tissues, we found that the overexpression of DNMT1 is positively correlated with the upregulation of KIT in tumor tissues. We demonstrated that DNMT1 and KIT form a positive regulatory loop, in which ectopic DNMT1 expression increases, whereas targeted DNMT1 depletion abrogates KIT signaling cascade through Sp1/miR-29b network. Conversely, an increase of KIT levels augments, but a reduction of KIT expression ablates DNMT1 transcription by STAT3 pathway leading to in-parallel modification of the DNA methylation profiles. We provided evidence that KIT inactivation induces global DNA hypomethylation, restores the expression of tumor suppressor p15INK4B through promoter demethylation; in turn, DNMT1 dysfunction impairs KIT kinase signaling. Functionally, KIT and DNMT1 co-expression promotes, whereas dual inactivation of them suppresses, lung cancer cell proliferation and metastatic growth in vitro and in vivo, in a synergistic manner. These findings demonstrate the regulatory and functional interplay between DNA methylation and tyrosine kinase signaling in propelling tumorigenesis, providing a widely applicable approach for targeting lung cancer.

Anti-mitotic agents: Are they emerging molecules for cancer treatment?

Mutations in cancer cells frequently result in cell cycle alterations that lead to unrestricted growth compared to normal cells. Considering this phenomenon, many drugs have been developed to inhibit different cell-cycle phases. Mitotic phase targeting disturbs mitosis in tumor cells, triggers the spindle assembly checkpoint and frequently results in cell death. The first anti-mitotics to enter clinical trials aimed to target tubulin. Although these drugs improved the treatment of certain cancers, and many anti-microtubule compounds are already approved for clinical use, severe adverse events such as neuropathies were observed. Since then, efforts have been focused on the development of drugs that also target kinases, motor proteins and multi-protein complexes involved in mitosis. In this review, we summarize the major proteins involved in the mitotic phase that can also be targeted for cancer treatment. Finally, we address the activity of anti-mitotic drugs tested in clinical trials in recent years.

Long-term survival for 93 months of limited-stage small cell lung cancer: A case report and literature review

A 49-year-old man was diagnosed with small cell lung cancer in May 2005. Chemotherapy was started with 60 mg/day cisplatin iv drip (from days one to three), 2 mg topotecan (TP) hydrochloride iv drip (from days one to four), and traditional Chinese medicine (TCM) AiDi injection for anti-tumor. After four cycles, he underwent conformal radiotherapy with 56Gy/28 fractions in October 2005. In April 2006, a mass on the right supraclavicular area was found. Therefore, he underwent another course of radiotherapy. The fields included the right supraclavicular area and the radiation dose was 50Gy/25 fractions. After completion of chemoradiotherapy, the patient achieved complete remission. Subsequently, the patient received prophylactic cranial irradiation (PCI). Until April of 2012, he had been followed up regularly. Since the SCLC diagnosis, he had received TCM for seven years. In April 2012, the patient complained of coughing again. Subsequently, the patient was given five cycles of an etoposide carboplatin regimen. A computed tomography (CT) scan was performed for review, which showed no obvious change. The patient underwent a second-line chemotherapy irinotecan cisplatin three times. However, the symptoms and CT of this patient showed no significant improvement. We changed the chemotherapy regimen to TP (topotecan 1.2 mg iv drip, days one to five; carboplatin 100 mg iv drip, days one to five). After two TP regimens, the patient died in his sleep on 3 March 2013. In this case, the standardized sequential chemotherapy and radiotherapy treatment, PCI, TCM, and good compliance may have contributed to the patient's longer survival.

Assessing the intracellular concentration of platinum in medulloblastoma cell lines after Cisplatin incubation

Two different analytical approaches, external calibration and isotope dilution analysis both using flow-injection inductively coupled plasma mass spectrometry, have been developed and applied to determine the intracellular platinum concentration after Cisplatin incubation of two different medulloblastoma cell lines (UW228 and DAOY). As the internal or isotopically enriched standard was already used for cell lysis, maximum accuracy of the results was obtained, whereas a new home-built and inert injection system dramatically lowered carry-over effects and analyte loss. With limits of the detection well below 0.4μgL(-1) and typical relative standard deviations of 2%, a strong correlation between the cell viability in MTT assays and the incorporated amount of Pt could be shown, which was subsequently normalized to the protein content of the samples. DAOY cells did significantly ingest more Pt and showed a higher mortality, which supports the fact that transporter expression needs to be taken into account in order to obtain meaningful results.