Acid Phosphatase

Biosensors for Cancer Biomarkers Based on Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles (MSNs) exhibit highly beneficial characteristics for devising efficient biosensors for different analytes. Their unique properties, such as capabilities for stable covalent binding to recognition groups (e.g., antibodies or aptamers) and sensing surfaces, open a plethora of opportunities for biosensor construction. In addition, their structured porosity offers capabilities for entrapping signaling molecules (dyes or electroactive species), which could be released efficiently in response to a desired analyte for effective optical or electrochemical detection. This work offers an overview of recent research studies (in the last five years) that contain MSNs in their optical and electrochemical sensing platforms for the detection of cancer biomarkers, classified by cancer type. In addition, this study provides an overview of cancer biomarkers, as well as electrochemical and optical detection methods in general.

Identification of acid phosphatase (ShACP) from the freshwater crab Sinopotamon henanense and its expression pattern changes in response to cadmium

Acid phosphatase(ACP) is an important immune enzyme in crustacean humoral immunity. At present, the research on ACP mainly focuses on the biochemical properties of the enzyme, while few studies on gene expression. In this study, ShACP was cloned and the effect of cadmium stress on the expression and function of ShACP in the freshwater crab Sinopotamon henanense was studied. Analysis of the ShACP sequence and tissue distribution results showed that the cDNA sequence of ShACP was 1629 bp, including 48 bp 5' untranslated region, 1209 bp open reading frame region, and 372 bp 3' untranslated region, encoding 402 amino acids. ShACP contained multiple phosphorylation sites and mainly played a role in the hemolymph. Under low-concentration cadmium stress, the body improved immunity by enhancing the expression of ShACP, while high-concentration cadmium stress inhibited the expression of ShACP. ShACP can promote the phagocytosis of hemocytes, while cadmium stress reduced the phagocytosis of hemocytes. This study provides a theoretical basis for further research on the immune system of crabs and is of great significance for the study of crustacean immune responses under heavy metal stress.

Discovery of Novel Thiazolidinedione-Derivatives with Multi-Modal Antidiabetic Activities In Vitro and In Silico

Diabetes mellitus (DM) and related complications continue to exert a significant burden on health care systems globally. Although conventional pharmacological therapies are beneficial in the management of this metabolic condition, it is still necessary to seek novel potential molecules for its management. On this basis, we have synthesised and evaluated the anti-diabetic properties of four novel thiazolidinedione (TZD)-derivatives. The TZD derivatives were synthesised through the pharmacophore hybridisation strategy based on N-arylpyrrole and TZD. The resultant derivatives at different concentrations were screened against key enzymes of glucose metabolism and glucose utilisation in the liver (HEP-G2) cell line. Additionally, peroxisome proliferator-activated receptor-γ activation was performed through docking studies. Docking of these molecules against PPAR-γ predicted strong binding, similar to that of rosiglitazone. Hence, TZDD2 was able to increase glucose uptake in the liver cells as compared to the control. The enzymatic inhibition assays showed a relative inhibition activity; with all four derivatives exhibiting ≥ 50% inhibition activity in the α-amylase inhibition assay and a concentration dependent activity in the α-glucosidase inhibition assay. All four derivatives exhibited ≥30% inhibition in the aldose reductase inhibition assay, except TZDD1 at 10 µg/mL. Interestingly, TZDD3 showed a decreasing inhibition activity. In the dipeptidyl peptidase-4 inhibition assay, TZDD2 and TZDD4 exhibited ≥20% inhibition activity.

Robust and Long-Term Cellular Protein and Enzymatic Activity Preservation in Biomineralized Mammalian Cells

Preservation of evolved biological structure and function in robust engineering materials is of interest for storage of biological samples before diagnosis and development of vaccines, sensors, and enzymatic reactors and has the potential to avoid cryopreservation and its associated cold-chain issues. Here, we demonstrate that "freezing cells in amorphous silica" is a powerful technique for long-term preservation of whole mammalian cell proteomic structure and function at room temperature. Biomimetic silicification employs the crowded protein microenvironment of mammalian cells as a catalytic framework to proximally transform monomeric silicic acid into silicates forming a nanoscopic silica shell over all biomolecular interfaces. Silicification followed by dehydration preserves and passivates proteomic information within a nanoscale thin silica coating that exhibits size selective permeability (<3.6 nm), preventing protein leaching and protease degradation of cellular contents, while providing access of small molecular constituents for cellular enzymatic reaction. Exposure of dehydrated silicified cells to mild etchant or prolonged hydrolysis removes the silica, completely rerevealing biomolecular components and restoring their accessibility and functionality.

Ready-to-Use Colorimetric Platform for Versatile Enzyme Assays through Copper Ion-Mediated Catalysis

A low cost and versatile colorimetric platform is developed for selective detections of various enzymes. Similar to peroxidases, free copper ion catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H₂O₂ and turns TMB into a blue product. Bindings from ligands toward copper ions inhibit this catalysis. Enzymes catalyze the reactions of related substrates with generation or consumption the ligands for the binding and thus in turn alter the color changes as responses toward the enzymes. With suitable substrates, exemplary enzymes, including trypsin, acid phosphatase, and tyrosinase, can be sensitively measured, with limits of detection of 0.003 μg/mL, 0.004 U/L, and 0.02 U/mL, respectively. This platform is built with directly available reagents, and the signals can be obtained with inexpensive photometers or visual observations. The low cost and convenience make it suitable for cases where complicated instrumentations are not available, such as point-of-care testing.

Micronutrient Fertilizers Affect the Digestibility, Intermediary Metabolism, and Oxidative Stress in Myzus persicae (Sulzer)

The green peach aphid, Myzus persicae(Sulzer) (Hemiptera: Aphididae), is an important pest of several worldwide crops. This study evaluated the effects of plant micronutrients (alpha-iron (Fe), zinc sulfate (Zn), copper sulfate (Cu), and manganese sulfate (Mn)) on digestive enzymes, intermediary metabolism, and antioxidant responses of M. persicae reared on bell pepper plants under greenhouse conditions. Results showed that M. persicae reared on Mn-treated plants had the digestive enzymes α-amylase, trypsin, chymotrypsin, and elastase inhibited. Moreover, the aphids fed on Mn-treated plants showed the highest activities of catalase, glucose-6-phosphate dehydrogenase, superoxide dismutase, and peroxidase, and lower increase rate of malondialdehyde. These findings indicate that micronutrients can impact the aphid metabolism, which may aid control strategies against this insect pest. We raise the potential for beneficial use of foliar fertilizer application as a pest management tool that could be further evaluated on a production and economical scale, as well as with other insect pests.

Kinetic Studies of Newly Patented Aminoalkanol Derivatives with Potential Anticancer Activity as Competitive Inhibitors of Prostate Acid Phosphatase

BACKGROUND

Acid phosphatase and its regulation are important objects of biological and clinical research and play an important role in the development and treatment of prostate and bone diseases. The newly patented aminoalkanol (4-[2-hydroxy-3-(propan-2-ylamino)propyl]-1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione hydrochloride) (I) and (4-[3-(dimethylamino)-2-hydroxypropyl]-1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione hydrochloride) (II) derivatives have potential anticancer activity, and their influence on enzymatic activity can significantly impact the therapeutic effects of acid phosphatase against many diseases. Therefore, in this study, we investigated the action of compounds (I) and (II) on acid phosphatase.

METHODS

Capillary electrophoresis was used to evaluate the inhibition of acid phosphatase. Lineweaver-Burk plots were constructed to compare the Km of this enzyme in the presence of inhibitors (I) or (II) with the Km in solutions without these inhibitors.

RESULTS

Compound (I) showed a stronger competitive inhibition against acid phosphatase, whereas derivative (II) showed a weaker competitive type of inhibition. The detailed kinetic studies of these compounds showed that their type and strength of inhibition as well as affinity depend on the kind of substituent occurring in the main chemical molecule.

CONCLUSIONS

This study is of great importance because the disclosed inhibition of acid phosphatase by compounds (I) and (II) raises the question of whether these compounds could have any effect on the treatment possibilities of prostate diseases.

Compound Cocktail Inhibits Influenza Viral Pneumonia via Phospholipase Cγ1 Phosphorylation-Related Necroptosis and Partial Autophagy in Natural Killer Cells

Influenza viral infections are prone to global outbreaks and cause pneumonia in affected populations. High morbidity and mortality caused by pneumonia occur during an influenza pandemic. Antivirals or control of inflammation is the primary means of influenza treatment. A compound cocktail composed of arctiin, daidzein, glycyrrhizic acid, and liquiritin inhibited mouse pneumonia resulting from a PR8 viral infection and caused a weight gain after oral administration. Natural killer cell activating receptors, both Ly49D and Ly49H in the lungs, were increased in the treatment in mice. In H3N2 virus-infected natural killer-92MI cells, the cocktail treatment had different effects on phosphorylation sites of phospholipase Cγ1 (PLCγ1) and killed infected cells through necroptosis or late apoptosis, in which RIP3 was increased and both caspase-3 and phosphorylated-JNK in the cells were downregulated. Acid phosphatase activity in viral-infected natural killer-92MI cells was induced by the compound cocktail treatment, which could be related to the p62 decrease in natural killer-92MI cells. In addition, an autophagic flux induction was observed in alveolar basal epithelial cells (A549). Protein p65, but not phosphorylated-p65, was significantly decreased by the treatment. Our results indicate that the compound cocktail strengthened the phosphorylation of PLCγ1-related necroptosis and partial autophagy in natural killer cells, which could yield an inhibitory effect on viral pneumonia in influenza.

Evidence That Speciation of Oxovanadium Complexes Does Not Solely Account for Inhibition of Leishmania Acid Phosphatases

Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, we investigate which oxovanadium starting material (orthovanadate or decavanadate) is a better inhibitor of L. tarentolae secreted acid phosphatase activity in vitro at the same total moles of vanadium. Considering speciation and total vanadium concentration, decavanadate is a consistently better inhibitor of SAP in our conditions, especially at low substrate:inhibitor ratios.

Comprehensive proteome analysis of lysosomes reveals the diverse function of macrophages in immune responses

Phagocytosis and autophagy in macrophages have been shown to be essential to both innate and adaptive immunity. Lysosomes are the main catabolic subcellular organelles responsible for degradation and recycling of both extracellular and intracellular material, which are the final steps in phagocytosis and autophagy. However, the molecular mechanisms underlying lysosomal functions after infection remain obscure. In this study, we conducted a quantitative proteomics analysis of the changes in constitution and glycosylation of proteins in lysosomes derived from murine RAW 264.7 macrophage cells treated with different types of pathogens comprising examples of bacteria (Listeria monocytogenes, L. m), DNA viruses (herpes simplex virus type-1, HSV-1) and RNA viruses (vesicular stomatitis virus, VSV). In total, 3,704 lysosome-related proteins and 300 potential glycosylation sites on 193 proteins were identified. Comparative analysis showed that the aforementioned pathogens induced distinct alterations in the proteome of the lysosome, which is closely associated with the immune functions of macrophages, such as toll-like receptor activation, inflammation and antigen-presentation. The most significant changes in proteins and fluctuations in glycosylation were also determined. Furthermore, Western blot analysis showed that the changes in expression of these proteins were undetectable at the whole cell level. Thus, our study provides unique insights into the function of lysosomes in macrophage activation and immune responses.

Altered endosome biogenesis in prostate cancer has biomarker potential

Prostate cancer is the second most common form of cancer in males, affecting one in eight men by the time they reach the age of 70 years. Current diagnostic tests for prostate cancer have significant problems with both false negatives and false positives, necessitating the search for new molecular markers. A recent investigation of endosomal and lysosomal proteins revealed that the critical process of endosomal biogenesis might be altered in prostate cancer. Here, a panel of endosomal markers was evaluated in prostate cancer and nonmalignant cells and a significant increase in gene and protein expression was found for early, but not late endosomal proteins. There was also a differential distribution of early endosomes, and altered endosomal traffic and signaling of the transferrin receptors (TFRC and TFR2) in prostate cancer cells. These findings support the concept that endosome biogenesis and function are altered in prostate cancer. Microarray analysis of a clinical cohort confirmed the altered endosomal gene expression observed in cultured prostate cancer cells. Furthermore, in prostate cancer patient tissue specimens, the early endosomal marker and adaptor protein APPL1 showed consistently altered basement membrane histology in the vicinity of tumors and concentrated staining within tumor masses. These novel observations on altered early endosome biogenesis provide a new avenue for prostate cancer biomarker investigation and suggest new methods for the early diagnosis and accurate prognosis of prostate cancer.

IMPLICATIONS

This discovery of altered endosome biogenesis in prostate cancer may lead to novel biomarkers for more precise cancer detection and patient prognosis.

Prostate cell lines as models for biomarker discovery: performance of current markers and the search for new biomarkers

BACKGROUND

Prostate cancer cell lines have been used in the search for biomarkers that are suitable for prostate cancer diagnosis. Unfortunately, many cell line studies have only involved single cell lines, partially characterized cell lines or were performed without controls, and this may have been detrimental to effective biomarker discovery. We have analyzed a panel of prostate cancer and nonmalignant control cell lines using current biomarkers and then investigated a set of prospective endosomal and lysosomal proteins to search for new biomarkers.

METHODS

Western blotting was used to define the amount of protein and specific molecular forms in cell extracts and culture media from a panel of nonmalignant (RWPE-1, PNT1a, PNT2) and prostate cancer (22RV1, CaHPV10, DU-145, LNCaP) cell lines. Gene expression was determined by qRT-PCR.

RESULTS

HPV-18 transfected cell lines displayed a different pattern of protein and gene expression when compared to the other cell lines examined, suggesting that these cell lines may not be the most optimal for prostate cancer biomarker discovery. There was an increased amount of prostatic acid phosphatase and kallikrein proteins in LNCaP cell extracts and culture media, but variable amounts of these proteins in other prostate cancer cell lines. There were minimal differences in the amounts of lysosomal proteins detected in prostate cancer cells and culture media, but two endosomal proteins, cathepsin B and acid ceramidase, had increased gene and protein expression, and certain molecular forms showed increased secretion from prostate cancer cells (P ≤ 0.05). LIMP-2 gene and protein expression was significantly increased in prostate cancer compared to nonmalignant cell lines (P ≤ 0.05).

CONCLUSIONS

While the existing prostate cancer biomarkers and lysosomal proteins investigated here were not able to specifically differentiate between a panel of nonmalignant and prostate cancer cell lines, endosomal proteins showed some discriminatory capacity. LIMP-2 is a critical regulator of endosome biogenesis and the increased expression observed in prostate cancer cells indicated that other endosome related proteins may also be upregulated and could be investigated as novel biomarkers.

Serum acid phosphatase can be a useful tumour marker for giant cell tumour of bone

INTRODUCTION

The purpose of this study was to elucidate the clinical significance of acid phosphatase in giant cell tumour of bone.

PATIENTS AND METHODS

Serum acid phosphatase levels were measured in 32 patients with this tumour both preoperatively and postoperatively.

RESULTS

Serum acid phosphatase value before surgery was high in 15 patients, whereas it was within normal limits in 17 patients. The serum acid phosphatase values of all the 15 patients with high preoperative serum level fell within normal limits postoperatively. In the remaining 17 patients in whom preoperative serum acid phosphatase values were within normal limits, postoperative serum acid phosphatase levels were lower than that of preoperative ones in all the patients. In addition, there was a statistically significant positive correlation between the tumour volume and the preoperative serum acid phosphatase level.

CONCLUSION

It is concluded that serum acid phosphatase is a useful tumour marker for giant cell tumour of bone.

Biomarkers of semen in the vagina: applications in clinical trials of contraception and prevention of sexually transmitted pathogens including HIV

Biomarkers of vaginal exposure to semen, long used in forensic medicine, are now becoming important in the development of vaginal microbicides to prevent HIV/STIs and the development of contraceptives. Semen biomarkers could help evaluate the safety of a new physical or chemical barrier, give preliminary indication of the effectiveness of physical barriers such as diaphragms or condoms, and provide information on unprotected intercourse among participants in a clinical trial who have been advised to use condoms. Candidate biomarkers of semen exposure fall into two broad categories: (1) biomarkers of seminal plasma, among which prostate-specific antigen (PSA) is the best characterized; and (2) biomarkers of spermatozoa and other cells present in semen. This paper, authored by a working group of investigators performing research in the field of semen biomarkers, summarizes the characteristics of an ideal semen biomarker, reviews preclinical and clinical data on existing and potential biomarkers, and outlines the steps that should be carried out to develop an improved biomarker of semen exposure.

A 60-kilodalton protein component of the counting factor complex regulates group size in Dictyostelium discoideum

Much remains to be understood about how a group of cells or a tissue senses and regulates its size. Dictyostelium discoideum cells sense and regulate the size of groups and fruiting bodies using a secreted 450-kDa complex of proteins called counting factor (CF). Low levels of CF result in large groups, and high levels of CF result in small groups. We previously found three components of CF (D. A. Brock and R. H. Gomer, Genes Dev. 13:1960-1969, 1999; D. A. Brock, R. D. Hatton, D.-V. Giurgiutiu, B. Scott, R. Ammann, and R. H. Gomer, Development 129:3657-3668, 2002; and D. A. Brock, R. D. Hatton, D.-V. Giurgiutiu, B. Scott, W. Jang, R. Ammann, and R. H. Gomer, Eukaryot. Cell 2:788-797, 2003). We describe here a fourth component, CF60. CF60 has similarity to acid phosphatases, although it has very little, if any, acid phosphatase activity. CF60 is secreted by starving cells and is lost from the 450-kDa CF when a different CF component, CF50, is absent. Although we were unable to obtain cells lacking CF60, decreasing CF60 levels by antisense resulted in large groups, and overexpressing CF60 resulted in small groups. When added to wild-type cells, conditioned starvation medium from CF60 overexpressor cells as well as recombinant CF60 caused the formation of small groups. The ability of recombinant CF60 to decrease group size did not require the presence of the CF component CF45-1 or countin but did require the presence of CF50. Recombinant CF60 does not have acid phosphatase activity, indicating that the CF60 bioactivity is not due to a phosphatase activity. Together, the data suggest that CF60 is a component of CF, and thus this secreted signal has four different protein components.

Serum total acid phosphatase for monitoring the clinical course of giant cell tumors of bone--26 patients with 5 local recurrences

BACKGROUND

Giant cell tumor of bone (GCT) is a bone-destroying tumor that sometimes recurs locally after treatment. A recent study showed increased levels of serum total acid phosphatase (TACP).

METHODS

We assessed TACP in the serum of 26 patients with primary GCT, and in 5 of them who developed a local recurrence.

RESULTS

We found a correlation between TACP level in serum and tumor size. TACP levels that were elevated preoperatively in patients with GCT became normalized after surgery, but increased in 3 of the 5 patients with local recurrence.

INTERPRETATION

TACP could be used as a tumor marker for monitoring response to treatment of GCT.

Prostatic acid phosphatase and prostate specific antigen in liver disease

Serum concentrations of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) were measured in 51 liver cirrhosis, 37 chronic active hepatitis (CAH) patients and 26 healthy individuals. Elevated PSA levels have been found in 2 of cirrhotic patients while no increase has been detected in CAH and controls. Serum PAP levels have been observed slightly increased in 2 patients with cirrhosis, 2 patients with CAH and 1 control case. Mean PSA and mean PAP values showed no significant difference between groups (p > 0.05). Serum PSA and PAP levels are reliable in diagnosing and monitoring prostate cancer in chronic liver patients and maintain their specificity in this situation.

Clinical use of tumor markers in oncology

The perfect tumor marker would be one that was produced solely by a tumor and secreted in measurable amounts into body fluids, it should be present only in the presence of cancer, it should identify cancer before it has spread beyond a localized site (i.e., be useful in screening), its quantitative amount in bodily fluids should reflect the bulk of tumor, and the level of the marker should reflect responses to treatment and progressive disease. Unfortunately, no such marker currently exists, although a number of useful but imperfect markers are available. The predominant contemporary markers are discussed here by chemical class, as follows: glycoprotein markers, including carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (beta-hCG), and prostate specific antigen (PSA); mucinous glycoproteins, including CA 15-3, CA 19-9, mucinous-like cancer antigen and associated antigens, and CA 125; enzymes, including prostatic acid phosphatase (PAP), neuron specific enolase (NSE), lactic acid dehydrogenase (LDH), and placental alkaline phosphatase (PLAP); hormones and related endocrine molecules, including calcitonin, thyroglobulin, and catecholamines; and, molecules of the immune system, including immunoglobulins and beta-2-microglobulin. The biologic properties of each group of tumor markers are discussed, along with our assessment of their role in clinical medicine today.

Prostate specific antigen: a critical assessment of the most useful tumor marker for adenocarcinoma of the prostate

PSA is a kallikrein-like, serine protease that is produced exclusively by the epithelial cells of all types of prostatic tissue, benign and malignant. Physiologically, it is present in the seminal fluid at high concentration and functions to cleave the high molecular weight protein responsible for the seminal coagulum into smaller polypeptides. This action results in liquefaction of the coagulum. PSA is also present in the serum and can be measured reliably by either a monoclonal immunoradiometric assay or a polyclonal radioimmunoassay. The calculated half-life of serum PSA ranges from 2.2 to 3.2 days and the metabolic clearance rate of this tumor marker follows first-order kinetics. Digital rectal examination, cystoscopic examination and prostate biopsy all can cause spurious elevations of the serum PSA concentration. Conditions such as bacterial prostatitis and acute urinary retention also can falsely elevate the serum PSA level. Because approximately 25% of the patients with BPH only will have an elevated serum PSA concentration and BPH tissue contributes to this PSA value in a variable manner from patient to patient, it is unlikely that PSA by itself will become an effective screening tool for the early diagnosis of prostate cancer. However, if combined with digital rectal examination and/or transrectal ultrasound it may become a vital part of any early detection program. Prostatic intraepithelial neoplasia also may be associated with moderately elevated serum PSA levels. Although there is a direct correlation between the serum PSA concentration and clinical stage, PSA is not sufficiently reliable to determine the clinical stage on an individual basis. This finding also applies to pathological stage. As a result, the preoperative serum PSA concentration cannot be used to decide whether to recommend radical prostatectomy for potential cure. Low preoperative serum PSA concentrations in patients with previously untreated prostate cancers are predictive of a negative bone scan. Thus, in these select patients a staging bone scintigram may not be necessary. With respect to monitoring patients after definitive therapy, PSA is an exquisitely sensitive tumor marker. Irrespective of the treatment modality (radical prostatectomy, radiation therapy or antiandrogen treatment), PSA reflects accurately the tumor status of the patient and is prognostic of eventual outcome; this tumor marker is capable of predicting tumor recurrence months before its detection by any other method. PSA is also a most useful immunocytochemical marker. Its sensitivity and specificity to identify tissue of prostatic origin approach 100%. When compared to PAP, PSA is a more precise and meaningful marker in all clinical situations.(ABSTRACT TRUNCATED AT 400 WORDS)

The role of serum prostatic acid phosphatase in the management of adenocarcinoma of the prostate with radiotherapy

Between 1974 and 1983, 472 patients with clinically-staged adenocarcinoma of the prostate treated by radiotherapy had baseline and follow-up prostatic acid phosphatase (SPAP) measurements by the enzymatic Roy method. The mean pretreatment SPAP was higher in Stage C (0.65 mIU/ml) than in combined Stages A2/B (0.43 mIU/ml), (p less than 0.05). Likewise, the incidence of elevated SPAP (greater than 0.8 mIU/ml) was also higher in Stage C (12%) than in Stages A2/B (3%), (p less than 0.01). Only 3 of 113 patients in Stages A2/B had an elevated SPAP and all three remain disease-free. In Stage C elevated SPAP was an adverse prognostic factor, and patients with a normal SPAP fared worse if their value was in the upper half of normal (greater than 0.4 mIU/ml) rather than in the lower half (less than or equal to 0.4 mIU/ml). However, in Stage C, tumor grade was found to correlate with initial SPAP, so that the higher the grade, the higher was the mean SPAP and the greater was the incidence of elevated SPAP. When stratified for grade, the prognostic significance of low-normal versus high-normal SPAP in Stage C was lost. An elevated SPAP was, however, an independent adverse prognostic factor for patients with intermediate and high grade tumors. Following radiotherapy, mean SPAP values fell significantly within 1-3 months. For patients with initially normal SPAP, this fall was of no prognostic significance. In 80% of the patients with baseline elevation of SPAP, the values normalized following treatment and the relapse rate in these patients was 51%, which was still higher than the relapse rate of patients with initially normal SPAP (33%) (p less than 0.05) but was lower than the 89% relapse rate in patients whose postradiation SPAP did not normalize (p less than 0.05). Pretreatment SPAP was of independent prognostic significance for only 6% of the study population and therefore has quite limited usefulness in the management of this disease. SPAP decreases following radiotherapy, but this is of prognostic significance only for the small group of patients with elevated pretreatment values.

Clinical experience with intra lymphatic administration of 111In-labelled monoclonal antibody PAY 276 for the detection of pelvic nodal metastases in prostatic carcinoma

The ability of 111In-PAY 276 (anti prostatic acid phosphatase antibody) in detecting pelvic lymph node metastasis following bipedal intra lymphatic administration was studied in five patients with carcinoma of the prostate. The labeled antibody was injected directly into the lymphatics of each foot. Planar and tomographic images radioactivity content of lymph nodes resected during staging pelvic lymphadenectomy were compared to the histologic and immunoperoxidase findings. Radioactivity in pelvic lymph nodes was prominently seen within 20 min of injection and was present 16 days later. Persistent accumulation of tracer in the lymphatics of the lower extremities was also observed in all patients 16 days post injection. Radioactivity counts in tumor-free lymph nodes were higher than in tumored lymph nodes resected. Our results demonstrate that intra lymphatic administration of 111In-labeled PAY 276 monoclonal antibody has major technical limitations, and that further research directed at the causes of tracer accumulation in the lymphatics and tumor-free lymph nodes is required.

Prostate specific antigen in the diagnosis and treatment of adenocarcinoma of the prostate. II. Radical prostatectomy treated patients

Serum prostate specific antigen was determined (Yang polyclonal radioimmunoassay) in 102 men before hospitalization for radical prostatectomy. Prostate specimens were subjected to detailed histological and morphometric analysis. Levels of prostate specific antigen were significantly different between patients with and without a Gleason score of 7 or greater (p less than 0.001), capsular penetration greater than 1 cm. in linear extent (p less than 0.001), seminal vesicle invasion (p less than 0.001) and pelvic lymph node metastasis (p less than 0.005). Prostate specific antigen was strongly correlated with volume of prostate cancer (r equals 0.70). Bivariate and multivariate analyses indicate that cancer volume is the primary determinant of serum prostate specific antigen levels. Prostate specific antigen was elevated 3.5 ng. per ml. for every cc of cancer, a level at least 10 times that observed for benign prostatic hyperplasia. Prostate specific antigen is useful as a preoperative marker because no patient with lymph node metastasis had serum levels of less than 10 ng. per ml. (4 times the upper limit of normal range). Of the patients with greater than 50 ng. per ml. two-thirds had microscopic lymph node metastasis and 90 per cent had seminal vesicle invasion. Serum prostatic acid phosphatase levels showed a significantly weaker correlation with cancer volume (r equals 0.51) and every other pathological parameter. Of the patients 73 per cent had serum prostatic acid phosphatase levels in the normal range (0 to 2.1 ng. per ml.), including 7 per cent who had pelvic lymph node metastasis. Postoperative prostate specific antigen values were available in 97 of 102 patients, with a mean and maximum followup of 12 and 38 months. No patient with pelvic lymph node metastasis achieved an undetectable prostate specific antigen level without adjunctive therapy (hormonal or radiation). No difference in preoperative or postoperative prostate specific antigen levels, cancer volume, seminal vesicle invasion or incidence of pelvic lymph node metastasis was seen between patients with no capsular penetration and those with minimal capsular penetration (1 cm. or less total linear extent of full thickness penetration), providing the first quantitative evidence that small amounts of capsular penetration may not be of biological or prognostic significance.

Present status of serum markers

Tumor markers presently in use generally meet only one or two of the criteria for the ideal marker, which are: tumor specificity, correlation with tumor bulk and stage of the disease, decrease to normal after successful treatment, and rise prior to clinical manifestations of recurrence. In addition, virtually all are elevated in some benign conditions. Currently their greatest usefulness is for confirmation of clinical suspicion and for monitoring known disease. Some tumor markers which are not effective as screening tests can be used to evaluate the patient's response to therapy. The discovery of oncogenes holds great promise for a new generation of tumor markers. Major breakthroughs in the fields of molecular biology and tumor immunology seem imminent with eventual application possibly in the treatment of cancer.

Comparative study of the clinical usefulness of prostate specific antigen and prostatic acid phosphatase in prostatic disease

The clinical usefulness of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) activity measurements has been compared in 45 patients with benign prostatic hyperplasia (BPH) and 132 patients with prostatic carcinoma (PC), 21 of whom had metastatic disease (MPC) and 111 of whom had intracapsular cancer. No BPH patient had increased PAP but 47% had increased PSA. Of the PC patients only 27% had increased PAP and 70% increased PSA. All of the MPC patients had increased PSA but only 62% had increased PAP. Increased PAP was found only in MPC but increased PSA was also found in BPH. In identifying PC, the predictive value of an increased PSA concentration is 83% and an increased PAP activity is 100%. On the other hand, the predictive value of a normal PSA concentration is 51% and of a normal PAP activity only 34%. As the PAP test is much less efficient than the PSA test, it should be discontinued.

Prostate-specific antigen as a serum marker for adenocarcinoma of the prostate

To compare the clinical usefulness of the serum markers prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP), we measured them by radioimmunoassay in 2200 serum samples from 699 patients, 378 of whom had prostatic cancer. PSA was elevated in 122 of 127 patients with newly diagnosed, untreated prostatic cancer, including 7 of 12 patients with unsuspected early disease and all of 115 with more advanced disease. The PSA level increased with advancing clinical stage and was proportional to the estimated volume of the tumor. The PAP concentration was elevated in only 57 of the patients with cancer and correlated less closely with tumor volume. PSA was increased in 86 percent and PAP in 14 percent of the patients with benign prostatic hyperplasia. After radical prostatectomy for cancer, PSA routinely fell to undetectable levels, with a half-life of 2.2 days. If initially elevated, PAP fell to normal levels within 24 hours but always remained detectable. In six patients followed postoperatively by means of repeated measurements, PSA--but not PAP--appeared to be useful in detecting residual and early recurrence of tumor and in monitoring responses to radiation therapy. Prostate massage increased the levels of both PSA and PAP approximately 1.5 to 2 times. Needle biopsy and transurethral resection increased both considerably. We conclude that PSA is more sensitive than PAP in the detection of prostatic cancer and will probably be more useful in monitoring responses and recurrence after therapy. However, since both PSA and PAP may be elevated in benign prostatic hyperplasia, neither marker is specific.

Correlation of clinical stage, serum prostatic acid phosphatase and preoperative Gleason grade with final pathological stage in 275 patients with clinically localized adenocarcinoma of the prostate

The usefulness of clinical stage, serum prostatic acid phosphatase and preoperative Gleason grade in predicting final pathological stage in patients with adenocarcinoma of the prostate remains controversial. To determine the predictive value of these 3 preoperative variables we reviewed 275 patients with clinically localized disease who were treated between April 1982 and February 1986. All patients were examined preoperatively and subsequently were operated upon by 1 urologist. Serum prostatic acid phosphatase was determined in all patients by the Roy method using thymolphthalein monophosphate as the substrate. The Gleason grade of each prostatic biopsy specimen was determined preoperatively by 1 pathologist, who also examined the final pathological specimen with respect to capsular penetration, and seminal vesicle and pelvic lymph node involvement. Using logistic regression analysis with the likelihood ratio chi-square test, clinical stage and Gleason grade had a direct correlation with capsular penetration (p less than 0.0001 and less than 0.0001, respectively), seminal vesicle involvement (p less than 0.0001 and less than 0.0001, respectively) and positive lymph nodes (p less than 0.0001 and less than 0.0002, respectively). Within the normal range of values (0.0 to 0.8 IU/l.) serum prostatic acid phosphatase correlated directly with capsular penetration (p less than 0.003) and seminal vesicle involvement (p less than 0.01) but not with lymph node involvement (p equals 0.08). Again with logistic regression analysis we determined that the best predictors of final pathological stage are not individual variables but models that use combinations of preoperative variables. The models generated are as follows: capsular penetration--serum prostatic acid phosphatase and Gleason grade (p less than 0.00001), seminal vesicle involvement--clinical stage and Gleason grade (p less than 0.00001), and lymph node involvement--clinical stage and Gleason grade (p less than 0.00001). With these models probability plots have been constructed so that the final pathological stage in patients with clinically localized prostatic cancer can be predicted preoperatively.

Rapid rise of serum acid phosphatase after irradiation of metastatic carcinoma of prostate

An eighty-two-year-old man with metastatic prostatic adenocarcinoma was treated with radiation therapy to the lumbar region of the spinal column. A rapid rise in his acid phosphatase activities developed, increasing thirty-eight-fold in two days. He died on the second day post-therapy of hemorrhagic complications. The rapid increase in acid phosphatase activity was due to release from injured or dying prostatic adenocarcinoma cells.

Significance of serum protein and lipid-bound sialic acid as a marker for genitourinary malignancies

A prospective study was done to evaluate the roles of serum N-acetylneuraminic acid (NANA) and the lipid-bound subfraction of sialic acid (LSA) concentrations in the detection and staging of cancer, and the follow-up of treatment in patients with genitourinary malignancies. Multiple determinations were obtained in 177 subjects: 90 normal volunteers, 38 patients with prostate cancer, 20 patients with bladder cancer, 15 patients with renal cell cancer, and 14 patients with benign urologic diseases. The results showed a low incidence of elevated values in patients with early stages of cancer and a high incidence of false-positive values with serum NANA concentrations in patients with benign urologic diseases, especially prostatitis. Serum NANA and LSA concentrations were highly correlated with the stage and grade in patients with advanced urologic cancer, and may be used as markers of tumor activity during follow-up under treatment; currently, however, they are not useful in the screening of patients for urologic cancer. Their usefulness in prostatic cancer is at least comparable to that of acid phosphatase determinations by the enzymatic and radioimmunoassay methods, which were elevated in a smaller percentage of patients with prostate cancer than were the NANA or LSA concentrations.

Two-dimensional characterization of prostatic acid phosphatase, prostatic specific antigen and prostate binding protein in expressed prostatic fluid

Specimens of pooled prostatic fluid, collected by rectal massage from men under 50 years of age with no apparent prostatic disorders, were subjected to two-dimensional gel electrophoresis to study the composition of its proteins. In a preliminary study, a total of 57 major protein groups were detected. In the present study, we attempted to identify, in the two-dimensional gels, those that are related to prostate-associated proteins, i.e., prostatic acid phosphatase (PAP), prostatic specific antigen (PSA), and prostate binding protein (PBP). Individual proteins were recognized by the procedure of Western Blot using specific antisera with peroxidase-antiperoxidase as the staining reagent. Each protein spot in the two-dimensional gel was expressed, along the abscissa, by its isoelectric point (pI) and, along the ordinate, by the molecular weight (MW). PAP consisted of a train of more than ten protein spots that occupied an area in the gel from pI 7.0, MW 45,000 to pI 6.0, MW 50,000. Four protein spots with a MW of 34,000 and a pI range of 8.2-8.8 were identified as PSA. PBP was observed as having three protein spots that were located at pI 5.6-6.6 with a single MW of 15,000. For PAP and PSA, additional protein spots with lower MWs also stained positively with the specific antisera, suggestive of the presence of degradative products of these proteins. Following the removal of the serum-related proteins by an extensive absorption with anti-human serum antibody by affinity chromatography, the prostatic fluid contained 27 major groups of non-serum proteins. These non-serum proteins in the prostatic fluid included PAP, PSA, PBP, and their related smaller molecular species. These results indicate that the prostatic fluid contains PAP, PSA, PBP and that their presence and the patterns of their distribution in the two-dimensional gels should be considered as the characteristic property of the prostatic secretions.

Tumor markers: value and limitations in the management of cancer patients

Sixteen tumor markers are reviewed, and measured to the ideal: produced by the tumor cell alone absent in health and in benign disease present in all patients with a given malignancy level in the blood representative of tumor mass detectable in occult disease. The only marker that approaches the ideal is human chorionic gonadotropin (HCG) in gestational trophoblastic tumors. In this malignancy, the HCG level suggests the diagnosis and stage, confirms response to therapy, and predicts relapse. The three most widely used and intensely studied tumor markers are carcinoembryonic antigen (CEA), alphafetoprotein (AFP), and HCG. CEA cannot be used in screening for cancer, but in carcinoma of the colon its elevation preoperatively increases the likelihood of advanced disease and postoperative recurrence. Postoperatively, elevated titers are often but not invariably associated with recurrent disease. AFP and HCG are useful in the management of nonseminomatous germ cell testicular tumors. Like CEA, they cannot be used for screening. They are more likely to be increased with advancing stage, and after therapy rising levels almost always mean recurrent disease. Some markers are valuable in specific circumstances, such as calcitonin in screening for familial medullary carcinoma of the thyroid. In multiple myeloma, immunoglobulins are useful in determining the tumor mass and response to therapy. In neuroblastoma, catecholamine metabolites are useful primarily in making the diagnosis. In some malignancies, the absence of effective therapy lowers the value of the marker, as for AFP in hepatoma. The remaining markers are too unreliable or too little studied to be useful in the management of an individual patient with cancer. The purpose of this paper is to provide the clinician with an understanding of the limitations of the present tumor markers that will lead to wiser use of the tests, and to provide standards to which future tumor markers should be measured.

Acid phosphatase in prostatic tissue homogenates from patients with benign prostatic hyperplasia and prostatic carcinoma

Acid phosphatase activity biochemically in the primary tumor of 20 patients with prostatic carcinoma, was studied in an attempt to understand the basis for a correlation or lack of correlation between serum and/or bone marrow acid phosphatase levels and the presence and/or clinical behavior of prostatic carcinoma. The enzyme activity was similarly measured in 19 patients with benign prostatic hyperplasia as controls. On the average, enzyme activities were lower (P less than 0.002) in the tissues from patients with carcinoma. There was no correlation of enzyme activity in tumor with the age of the patient, stage of disease, degree of differentiation of the tumor, or serum acid phosphatase activity.

Prostatic acid phosphatase: comparison of radioimmunoassay and enzyme activity assay

Aspects of the clinical use of an enzymatic assay and a double antibody radioimmunoassay for prostatic acid phosphatase are compared. Standard blood sample collection and transport did not have a negative effect on the results of either assay. Our results show no substantial advantage in the use of a radioimmunoassay but emphasize the reliability of the enzymatic assay using alpha-naphthylphosphate as a substrate with respect to its predictive value and specificity in diagnosis and followup of patients with prostatic carcinoma.

Serial spot hydroxyproline/creatinine ratios in metastatic prostatic cancer

Analysis of urinary hydroxyproline levels offers a marker to monitor osseous involvement in patients with metastatic malignancies. Such a marker is needed in patients with prostatic cancer when bone metastases predominate. Thirty-two men with stage D2 prostatic cancer were monitored by bone scan, acid and alkaline phosphatase values, and urinary hydroxyproline, beginning from 4 to 36 months after initiation of hormonal manipulation and/or systemic chemotherapy. In patients with disease progression determined by bone scan serial urinary hydroxyproline values progressively increased and were significantly elevated compared to urinary values obtained from patients with a stable or improving scan (p less than 0.001). Simultaneous alkaline phosphatase determinations showed less significant differences between patient groups. Acid phosphatase did not reliably indicate osseous response to therapy. These data suggest that urinary hydroxyproline values are predictive as an early objective sign of osseous response in patients receiving therapy for stage D2 prostatic cancer.

Use of urinary hydroxyproline excretion as a tumor marker in diagnosis and follow-up of prostatic carcinoma

Urinary hydroxyproline/creatinine ratio was measured in 49 patients of prostatic carcinoma and 13 patients with benign prostatic hypertrophy, the latter group serving as controls. The results show that it is a very sensitive indicator of osseous metastases in prostatic carcinoma. The ratio was also measured in 18 patients of prostatic carcinoma with bony metastases before commencement of treatment and during treatment. The results show that the elevated pretreatment values were significantly reduced in those who responded to therapy whereas in nonresponders, the values remained high. Changes in urinary hydroxyproline appeared to reflect the nature of response to treatment better than other parameters.