Nuclear magnetic resonance analysis of cell metabolism

Characterization of ovarian cancer cell metabolism and response to chemotherapy by (31)p magnetic resonance spectroscopy

We aimed to characterize the (31)P magnetic resonance spectra of various ovarian cancer cell lines exhibiting differences in cytotoxic drug resistance. We examined the metabolic profile of three different ovarian cancer cell lines, OC238, A2780, and A2780-cisplatin resistant (A2780cisR), including their response to various cytotoxic drugs (paclitaxel, cisplatin, and carboplatin) by (31)P magnetic resonance spectroscopy (MRS) in vitro. In the OC238 cell line, there were higher levels of phosphorylcholine, phosphodiesters, and uridine diphosphosugar (UDPS) + nicotinamide adenine dinucleotide phosphate (NADP). In A2780 and A2780cisR cell lines, phosphocreatine gave a high signal, which was absent in the OC238 cell line. In the OC238 cell line, a significant decrease in the glycerophosphoethanolamine, glycerophosphocholine, NADP, and UDPS signals was detected following cytotoxic drug treatment, mainly in response to paclitaxel. A significant increase in the glycerophosphocholine signal was detected following exposure to paclitaxel in both A2780 and A2780cisR cell lines. NADP and UDPS signals increased in response to all drugs in the A2780 cell line; however, in the cisplatin-resistant cell line A2780cisR, no significant change in those signals was detected following cisplatin treatment. We conclude that different ovarian cancer cell lines show characteristic (31)P MRS fingerprints and specific metabolic changes in response to cytotoxic drug treatment.

Ex vivo 1H and 31P magnetic resonance spectroscopy as a means for tumor characterization in ovarian cancer patients

We aimed to determine whether cells obtained from malignant ovarian tumors had different ex vivo 1H- and 31P (phosphorus-31)-magnetic resonance (MR) spectra compared to cells obtained from benign ovarian cysts. In addition, we aimed to assess the metabolic effects of chemotherapy on malignant cells obtained from peritoneal effusions of ovarian cancer patients. We included 20 ovarian cancer patients undergoing explorative laparotomy for tumor resection, 15 patients undergoing oophorectomy for benign ovarian cysts and 8 patients with advanced ovarian cancer with cancerous peritoneal effusion undergoing palliative percutaneous drainage. Ovarian and metastatic tissues were obtained from all patients undergoing laparotomy and analyzed using 1H magnetic resonance spectroscopy (MRS). Cancerous cells from peritoneal effusions were incubated with 3 different anti-mitotic drugs (paclitaxel, cisplatin and carboplatin) at LC50 and the consequent metabolic changes were monitored using 31P-MRS. 1H-MRS revealed significantly higher intracellular lactate levels in cells obtained from ovarian tumors, most prominently in the moderately to poorly differentiated histological types, while total choline (Chol) compounds were higher in the moderately to poorly differentiated subgroup only. Ovarian cancer cells obtained from peritoneal effusions showed a significantly decreased glycerophosphocholine (GPC), glycerophosphoethanolamine (GPE) and uridine diphospho-sugar (UDPS) levels following ex vivo exposure to all 3 anti-mitotic drugs. Ex vivo 1H-MRS identified significant metabolic differences between cells obtained from ovarian tumors compared to those originating in benign ovarian cysts, including increased lactate and total choline compound levels. The 31P-MRS technique allowed characterization and monitoring of metabolic changes occurring in ovarian cancer cells in response to chemotherapy.

New advances in MR-compatible bioartificial liver

MR-compatible bioartificial liver (BAL) studies have been performed for 30 years and are reviewed. There are two types of study: (i) metabolism and drug studies using multinuclear MRS; primarily short-term (< 8 h) studies; (ii) the use of multinuclear MRS and MRI to noninvasively define the features and functions of BAL systems for long-term liver tissue engineering. In the latter, these systems often undergo not only modification of the perfusion system, but also the construction of MR radiofrequency probes around the bioreactor. We present novel MR-compatible BALs and the use of multinuclear MRS ((13)C, (19)F, (31)P) for the noninvasive monitoring of their growth, metabolism and viability, as well as (1)H MRI methods for the determination of flow profiles, diffusion, cell distribution, quality assurance and bioreactor integrity. Finally, a simple flexible coil design and circuit, and life support system, are described that can make almost any BAL MR-compatible.

Intelligent bioprocessing for haemotopoietic cell cultures using monitoring and design of experiments

The need for successful ex-vivo expansion and directed differentiation of haematopoietic stem cells (HSCs) for therapeutic applications has increased over the past decade. Haematopoietic cell cultures are complex and full characterisation of the process environment has yet to be achieved. The complexity and transient nature of HSC cultures make the identification, maintenance and control of optimal operating conditions challenging. Application of real-time, on-line monitoring techniques and process control strategies enhances the ability to operate bioprocesses of desired reproducibility and high product quality. In this review, we discussed the methods by which in vitro culture information necessary for bioprocess control may be obtained, including process considerations, monitoring and analytical tools, and design of experiments (DOE). The successful application of these tools may result in time- and cost-effective cultures for directed differentiation and expansion of haematopoietic components intended for clinical use.

Metabolic mapping with bioluminescence: basic and clinical relevance

This review is focused on metabolic mapping in biological tissue with quantitative bioluminescence and single photon imaging. Metabolites, such as ATP, glucose and lactate, can be imaged quantitatively and within microscopic dimensions in cryosections from shock frozen biological specimens using enzyme reactions and light emission by luciferases. The technique has been applied in numerous targets and models of experimental biomedical research, such as multicellular spheroids, various organs of laboratory animals in a physiological or pathophysiological state, and even in plant seeds. Among numerous other aspects, data obtained with this method have contributed to the elucidation of mechanisms that are involved in the development of necrosis in multicellular spheroids. The combination of the bioluminescence technique with immunohistochemistry, autoradiography or in situ hybridization can considerably reduce ambiguities in the interpretation of the experimental results. Although, an invasive technique, bioluminescence imaging has been used most intensively in clinical oncology using tumor biopsies taken at the first diagnosis of the disease. It has been shown for squamous cell carcinomas of the head and neck and of the uterine cervix that accumulation of high levels of lactate in the primary lesions is associated with a high risk of metastasis formation and a reduced overall and disease-free patient survival. Thus, metabolic imaging can provide additional information on the degree of malignancy and the prognosis of tumors which may help the oncologist in improving specific treatment approaches for each individual malignant disease. Last but not least, metabolic mapping in clinical oncology has stimulated a number of investigations in basic cancer research on mechanisms that underlie the correlation between tumor metabolism and malignancy.