Evaluation of Serum Sarcosine, Total and Free Testosterone Levels in Patients with Prostate Disorders in Sokoto, Nigeria.

Although radiation and surgery are generally regarded as effective for treatment of prostate cancer (PCa) in majority of men, diagnosis and prognosis remains poor in patients with progressive disease. Disease –specific metabolites represent the effective end points with considerable ability to identify men at increased risk of disease progression. In the current study, serum levels of Sarcosine, free and total testosterone (fTesto and tTesto) were assayed to evaluate the tumorigenic properties of PCa in our locality. In this study, 150 prostate cancer, 200 benign prostatic hyperplasia (BPH) Patients diagnosed and 200 volunteer matched controls were evaluated. Serum sarcosine were 64.94±0.81 nmol/dl, 118.70±1.80 nmol/dl and 134.13±2.21 nmol/dl in PCa, BPH patients and controls respectively. Serum tTesto and fTesto levels were 5.09±0.15 ng/ml, 5.12±0.11 ng/ml and 13.42±0.26 pg/ml, 5.72±0.20 ng/ml, 13.93±0.24 ng/ml and 11.73±0.47 pg/ml in PCa, BPH patients and controls respectively. Values differ significantly (p˂0.05) between PCa, BPH patients and controls in all the analytes. Attempt was also made to define the reference ranges of these analytes in various age groups of the controls. We recommend the inclusion of Serum levels of Sarcosine, tTesto and fTesto into multiplex biomarker panel for PCa and BPH detection in our localities.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the quantification of creatinine-corrected sarcosine in urine / 中华检验医学杂志

Objective To establish a liquid chromatography-tandem mass spectrometry ( LC-MS/MS) method for the quantification of creatinine-correctedsarcosine in urine for the prostate cancer diagnosis and treatment.Methods It performed the method establishment and evaluation in this study.Random unrine samples were collected from 36 subjects with prostate cancer, 15 subjects with benign prostatic hyperplasia and 76 healthy people receiving medical examination.Urine samples mixed with [ 2 H3 ]-labeled sarcosine were treated by precolumn derivation using dansyl chloride, then analyzed by LC-MS/MSsystem in multiple reaction monitor ( MRM) mode.Sarcosine and creatinine were quantified by the isotope internal standard method and the standard curve was employed with a series of calibration.The limit of detection, precision and recovery were also evaluated in this study.The results of this methodology were compared with those of the enzymatic method.Results Sarcosine could be distinguished against its isomers completely. The linear equation of sarcosine was Y=2.045 6X+0.068 9, R2 =0.994.The limit of detection and limit of quantity were 8 ng/ml and 25 ng/ml respectively.The intraassay and interassay coefficients of variation were both below 6%.The recovery ratio of sarcosine ranged from 96.8%to 105.1%.The results from the ID-LC-MS method correlated with those from enzymatic method (R2 =0.815, P <0.01).Compared to enzymatic method, the average bias of sarcosine was -37.1%.Conclusions It established a LC-MS method for urinary sarcosine quantification with good specificity, sensitivity and repeatability.This method can provide a reliable platform for the diagnosis of prostate cancer.

Expression of Sarcosine Metabolism-Related Proteins in Invasive Lobular Carcinoma: Comparison to Invasive Ductal Carcinoma

PURPOSE: The aims of this study were to compare the expression of sarcosine metabolism-related proteins between invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) and to determine the implications of these results. MATERIALS AND METHODS: Tissue microarrays were constructed, containing 30 samples from normal breast tissue, 114 samples from patients with ILC, and 692 samples from patients with IDC. Immunohistochemical staining was performed to examine the expression of sarcosine metabolism-related proteins [glycine N-methyltransferase, sarcosine dehydrogenase, and l-pipecolic acid oxidase (PIPOX)]. RESULTS: The sarcosine metabolic phenotype differed between ILC and IDC (plow sarcosine type (30.4%)>high sarcosine type (5.0%)>intermediate type (2.9%). However, in ILC, the sarcosine metabolic phenotype was distributed as low sarcosine type (61.4%)>null type (32.5%)>intermediate type (5.3%)>high sarcosine type (0.9%). PIPOX showed higher expression in ILC than in IDC (p<0.001) and correlated with androgen receptor (AR) positivity (p=0.001) in ILC. CONCLUSION: Expression of sarcosine metabolism-related proteins differed between ILC and IDC. Low sarcosine type was the majority sarcosine metabolic phenotype of ILC. PIPOX expression was predominant in ILC and correlated with AR positivity.

The effect of calcium dobesilate on creatinine measurement by sarcosine oxidase assay / 中华检验医学杂志

Objective To investigate the interference effect of calcium dobesilate on serum creatinine levels by Sarcosine oxidase-based assay.Methods 1.Interference test in vivo:Ten patients with chronic renal diseases from Huangshi second hosptial were recruited.Serum creatinine (sarcosine oxidase method,Scr1 ; deiminase method,Scr2),urea,and cystatin C were detected and compared before and after one week administration of calcium dobesilate; 2.Interference test in vitro:to detect whether 100 mg/L calcium dobesilate has any interference with Scr1 and Scr2; 3.Dose-dependent interference test:To detect the interference effect of different concentrations of calcium dobesilate (1.25-20.0 mg/L) on different creatinine concentrations (404.5 μmol/L or 65.9 μmoL/L) measured by sarcosine oxidase assay.Bias within 3.5％ or 6.63 μmol/L of creatinine levels was clinically acceptable.Statistical comparisons were made using Wilcoxon rank-sum test.Results There was significant difference of sarcosine oxidase-based serum creatinine levels between before and after one week administration of calcium dobesilate (P ＜ 0.05),while no significant differences were observed for deiminase-based serum creatinine levels,urea and estimated GFR values (P ＞ 0.05).Interference test showed that 95％ confidence interval of interventional value (Dobs) of calcium dobesilate (100 mg/L) was (-173.9 ± 2.86) μmol/L for the sarcosine oxidase assay and (1.21 ± 3.14) μmol/L for deiminase method,indicating that calcium dobesilate caused a significant negative effect on the former enzymatic assay but not the latter one.In the dose effect interference test of calcium dobesilate,the regression equations were:Y =-2.7649X-0.0782 (R2 =0.998,F =7943.4,P =0.000) for high creatinine levels and Y =0.0263X2-1.6394X-0.2754 (R2 =0.996,F =2546.7,P =0.000) for low creatinine levels.The interference effect was less than the predetermined d with the calcium dobesilate concentrations of 4.4 mg/L in high concentration specimen and 3.5 mg/L in low concentration specimen.Conclusions Calcium dobesilate has a significant negative interference with serum creatinine detected by the sarcosine oxidase method,which leads to the bias of creatinine in patients with renal insufficiency.Hence,sarcosine-oxidase-based creatinine levels should be cautious when calcium dobesilate was used,and further check with another assay is necessary if possible.