Production of N1-acetyl spermidine by renal cell tumors

Use of amantadine in the evaluation of response to chemotherapy in lung cancer: a pilot study

Aim:

The assessment of tumor response to therapy is of critical importance as it permits for a prospective end point evaluation and provides a guide to clinicians for making future treatment decisions. However, current practices in early evaluation of chemotherapy are insufficient. Amantadine is a substrate for SSAT-1. The present pilot study tests the hypothesis that SSAT-1 activity within the tumor, as measured by plasma acetylamantadine concentrations, can be used to monitor patient response to therapy.

Results:

In cases with evidence of disease response, there was a reduction in the plasma acetylamantadine concentration at 4 h by approximately 32%. There was a mean increase of approximately 34% at the 4 h collection in the nonresponders.

Conclusion:

Although large-scale studies are required these findings suggest that the amantadine test could allow for determination of the efficacy of therapeutic interventions earlier, providing an effective test to assess response to treatment and for better management of patients.

Aim: It is very important to get early information on the effectiveness of tumor treatment such that clinicians have a better understanding and decide on the next treatment regimen. Current methods are not sufficient to assess whether chemotherapy is effective early during a treatment cycle. We have previously used the presence of the acetylated metabolite of the drug amantadine in urine of patients diagnosed with lung cancer as a biomarker for disease. In the present study, our goal was to test the hypothesis that tumor responsiveness to therapy could be assessed by monitoring changes in the levels of the acetylated form of amantadine in the blood during the course of treatment. Results: In 70% of the patients we were able to relate disease progression or remission/stability to the levels of the acetylated form of amantadine in the blood. Conclusion: Although a larger study with a greater number of patients is required, our test could be used as a simple and effective tool to assess response to treatment and to better tailor treatment of the patient as well as reduce side effects and costs.

Liquid Biopsy in Lung Cancer Screening: The Contribution of Metabolomics. Results of A Pilot Study

Background: Lung cancer is the most common cause of cancer-related deaths worldwide. Early diagnosis is crucial to increase the curability chance of the patients. Low dose CT screening can reduce lung cancer mortality, but it is associated with several limitations. Metabolomics is a promising technique for cancer diagnosis due to its ability to provide chemical phenotyping data. The intent of our study was to explore metabolomic effects and profiles of lung cancer patients to determine if metabolic perturbations in the SSAT-1/polyamine pathway can distinguish between healthy participants and lung cancer patients as a diagnostic and treatment monitoring tool. Patients and Methods: Plasma samples were collected as part of the SSAT1 Amantadine Cancer Study. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify and quantify metabolite concentrations in lung cancer patient and control samples. Standard statistical analyses were performed to determine whether metabolite concentrations could differentiate between healthy subjects and lung cancer patients, as well as risk prediction modeling applied to determine whether metabolic profiles could provide an indication of cancer progression in later stage patients. Results: A panel consisting of 14 metabolites, which included 6 metabolites in the polyamine pathway, was identified that correctly discriminated lung cancer patients from controls with an area under the curve of 0.97 (95% CI: 0.875-1.0). Conclusion: When used in conjunction with the SSAT-1/polyamine pathway, these metabolites may provide the specificity required for diagnosing lung cancer from other cancer types and could be used as a diagnostic and treatment monitoring tool.

Spermidine/spermine N1-acetyltransferase-1 as a diagnostic biomarker in human cancer

Aim:

SSAT-1 is an enzyme that plays a critical role in cell growth. Amantadine, a FDA-approved antiviral drug, is a substrate for SSAT-1. The utility of amantadine as an agent to demonstrate elevated SSAT-1 activity linked to cancer was conducted.

Results:

High levels of SSAT-1 expression were measured in tumor human cell lines, and in breast, prostate and lung tumor tissue. An increase in the urinary levels of acetylated amantadine in cancer patients was observed.

Conclusion:

Increases in SSAT-1 contents in tumor tissue could be of value in targeting cancers with high SSAT-1 expression for confirmation/quantification. The high levels of acetylated amantadine could be used as a simple and useful screening test for the presence of cancer.

In response to cancer, cells tend to overproduce specific enzymes as a self-defense mechanism. By using a safe and reliable method to capture and measure the excess enzyme spermidine/spermine N1-acetyltransferase-1, the presence of cancer can be established. This study describes a novel approach of detecting and screening cancer noninvasively in the urine of cancer patients using a safe and approved drug called amantadine that acts as a smart-tracking agent. Higher levels of the acetylated form of amantadine are detectable in the urine of cancer patients, which may serve as a detection tool. In addition, increases in the amount of spermidine/spermine N1-acetyltransferase-1 in tumor tissue may provide a tool for determining the presence of cancer during pathology assessment.

Polyamine acetylation in rat brain during N-ethyl-N-nitrosourea-induced cerebral carcinogenesis

The behavior of cerebral polyamine acetylation was examined in rat brain during N-ethyl-N-nitrosourea-induced carcinogenesis. Before tumor development, treated brains exhibited an enhancement in cytosolic spermidine/spermine N1-acetyl-transferase activity with concomitant accumulation of N1-acetylspermidine and increases in putrescine and spermidine. This indicates a stimulation of the interconversion pathway of polyamines into putrescine, an important molecule for cell growth. Our data also show the presence of a cytosolic spermidine N8-acetyltransferase activity in fetal rat brain, with values similar to those previously observed in gliomas. The detection of cytosolic spermidine N8-acetyltransferase activity in tumors may thus represent the expression of a fetal gene that does not seem to have a particular function during carcinogenesis.

Antiproliferative effects of interferon gamma in combination with alpha-difluoromethylornithine on human carcinoma cell cultures

The antiproliferative effects of human recombinant interferon gamma (IFN gamma) in combination with alpha-difluoromethylornithine (DFMO) or as single agents were assessed on human cell cultures derived from carcinomas of the breast (MCF-7), the ovary (EFO-27) or the kidneys (EGI-4). Results were obtained in proliferation assays by direct cell counting. The cell lines differed considerably in their sensitivities to the antiproliferative effect of IFN gamma as compared by the 50% inhibition doses of the growth (ID50). In contrast to the findings with IFN gamma, similar antiproliferative effects resulted from the application of comparable doses of DFMO. While IFN gamma induced cytotoxic effects in EGI-4 cells, DFMO produced only cytostatic actions in the cell lines analyzed. Synergistic growth inhibition resulted from the combined application of IFN gamma and DFMO in EFO-27 cell cultures. This finding was most pronounced after treatment with IFN gamma or DFMO doses below the respective ID50 values. However, antagonistic effects occurred in cells of the line EGI-4 after DFMO had been combined with IFN gamma at concentrations below the cytotoxic dose range. Within the sensitivity of our proliferation assay, no synergistic interactions were found in MCF-7 cell cultures. In the cell lines tested, no relation between the sensitivity for the single agents and the effectivity of the drug combination was identified. Despite promising synergistic effects in the moderately IFN gamma-sensitive ovarian carcinoma cell line EFO-27, the efficacy of the IFN gamma/DFMO combination was restrained by possible antagonistic effects as demonstrated in the highly IFN gamma-sensitive EGI-4 renal carcinoma cell cultures. We conclude that the differential interaction patterns in the cell cultures analyzed preclude general suggestions for clinical studies using IFN gamma and DFMO.

Increased synthesis of N1-acetylspermidine in hepatic preneoplastic nodules and hepatomas

Hepatic preneoplastic nodules and hepatomas obtained in a multistep protocol of rat hepatocarcinogenesis (diethylnitrosamine, 2-acetylaminofluorene, and partial hepatectomy) showed high values of spermidine N1-acetyltransferase activity, the rate-limiting enzyme in polyamine interconversion. Such an increase was associated with the appearance of N1-acetylspermidine, an enhancement in putrescine, and a decline in spermine. Such changes suggest an activation of the interconversion pathway of high into lower polyamines in hepatic preneoplastic nodules and hepatomas.