Cardiotoxicity of mitomycin A, mitomycin C, and seven N7 analogs in vitro

Synthesis of N-H Aziridines from Unactivated Olefins Using Hydroxylamine-O-Sulfonic Acids as Aminating Agent

Herein, we presented a practical methodology for the intermolecular aziridination of alkenes, using HOSA as the aminating agent, alongside pyridine or piperidine as the base, within HFIP solvent system. Notably, this approach showcases excellent reactivity, especially with nonactivated alkenes, and facilitates the transformation of various alkenes substrates, including mono-, di-, tri, and tetra-substituted alkenes, into aziridines with moderate to excellent yield. This method presents a promising avenue for synthesizing aziridines from a wide range of alkenes, featuring the benefits of straightforward operation, mild reaction conditions, extensive substrate compatibility, and scalability.

Chemotherapeutic-Induced Cardiovascular Dysfunction: Physiological Effects, Early Detection-The Role of Telomerase to Counteract Mitochondrial Defects and Oxidative Stress

Although chemotherapeutics can be highly effective at targeting malignancies, their ability to trigger cardiovascular morbidity is clinically significant. Chemotherapy can adversely affect cardiovascular physiology, resulting in the development of cardiomyopathy, heart failure and microvascular defects. Specifically, anthracyclines are known to cause an excessive buildup of free radical species and mitochondrial DNA damage (_mtDNA) that can lead to oxidative stress-induced cardiovascular apoptosis. Therefore, oncologists and cardiologists maintain a network of communication when dealing with patients during treatment in order to treat and prevent chemotherapy-induced cardiovascular damage; however, there is a need to discover more accurate biomarkers and therapeutics to combat and predict the onset of cardiovascular side effects. Telomerase, originally discovered to promote cellular proliferation, has recently emerged as a potential mechanism to counteract mitochondrial defects and restore healthy mitochondrial vascular phenotypes. This review details mechanisms currently used to assess cardiovascular damage, such as C-reactive protein (CRP) and troponin levels, while also unearthing recently researched biomarkers, including circulating _mtDNA, telomere length and telomerase activity. Further, we explore a potential role of telomerase in the mitigation of mitochondrial reactive oxygen species and maintenance of _mtDNA integrity. Telomerase activity presents a promising indicator for the early detection and treatment of chemotherapy-derived cardiac damage.

A pilot study of three-dimensional conformal radiotherapy in unresectable hepatocellular carcinoma

BACKGROUND

The purpose of this study was to determine the potential role of three-dimensional (3-D) conformal radiotherapy (RT) in treatment of unresectable hepatocellular carcinoma (HCC).

METHODS

Thirteen patients were included in this study, which was conducted between 1993 and 1996. Nine patients (group A) were treated with 3-D conformal RT alone because of main portal vein thrombosis, inferior vena cava thrombosis, obstructive jaundice and failure of previous transcatheter arterial chemoembolization (TACE) to control the disease. The remaining four patients (group B) were treated with a combination of TACE and 3-D conformal RT.

RESULTS

The greatest dimension of the main tumour in the whole group of patients ranged from 6 to 25 cm (median 15 cm). The radiation dose ranged from 40 to 60 Gy. The tumour response was evaluated by computed tomography scans of the liver 6-8 weeks after completion of radiotherapy. Partial response was observed in 58% of the patients (seven of 12) and minimal response in another 25% of patients (three of 12). One patient could not be evaluated because of the development of hepatic failure 1 month after completion of RT. All patients in group B lived for more than 1 year (range 16-40 months). In group A, one patient who had a large tumour (11 x 10 x 21 cm) with portal vein thrombosis was converted to become resectable after 45 Gy of radiation. The resection specimen revealed no residual cancer cells. This patient is alive longer than 15 months after treatment without the evidence of disease.

CONCLUSIONS

Our experience indicates that HCC is more radiosensitive than it was traditionally expected. Three-dimensional reconstruction of tumour and surrounding organs helps to avoid excessive exposure of the liver and adjacent organs to RT and makes it a safer treatment modality for unresectable HCC. Our preliminary data show promise and are worthy of further study to explore the potential role of radiotherapy in the treatment strategy for HCC at various stages of involvement.

Phase I study of the mitomycin C analogue BMS-181174

BMS-181174 is an aminodisulphide derivative of Mitomycin C (MMC) with activity against a range of tumour cell lines and xenografts, including MMC-resistant tumours. In a phase I study of 82 patients with confirmed malignancy, we administered BMS-181174 at doses of 0.8-75 mg m(-2) by intravenous injection every 28 days. At least three patients were evaluated at each dose level, and 174 courses were administered. The pharmacokinetics were dose linear at BMS-181174 doses of 11.5-75 mg m(-2) and the drug appeared to undergo wide distribution. The maximum-tolerated dose was 65 mg m(-2) in previously treated patients and 75 mg m(-2) in chemotherapy-naive cases. The dose-limiting toxicity was myelosuppression, particularly thrombocytopenia, which was prolonged and cumulative. Three patients treated at 65-75 mg m(-2) died suddenly with evidence of pneumonia/pneumonitis, thought to be drug-related. Other toxicities included thrombophlebitis, possible cardiotoxicity (asymptomatic, reversible decline in left ventricular function) and renal impairment. The partial response rate was 5% (4 out of 82) overall, and 9% (3 out of 32) in patients treated at 65-75 mg m(-2). Responses occurred in treated and previously-untreated patients, including cases of colorectal cancer, non-small-cell lung cancer, ovarian cancer and adenocarcinoma of unknown primary site. BMS-181174 has anti-cancer activity but, because of its toxicity, particularly pneumonitis and thrombophlebitis, no phase II studies are planned.