Sonic hedgehog (Shh) signaling promotes tumorigenicity and stemness via activation of epithelial-to-mesenchymal transition (EMT) in bladder cancer.

Activation of the sonic hedgehog (Shh) signaling pathway controls tumorigenesis in a variety of cancers. Here, we show a role for Shh signaling in the promotion of epithelial-to-mesenchymal transition (EMT), tumorigenicity, and stemness in the bladder cancer. EMT induction was assessed by the decreased expression of E-cadherin and ZO-1 and increased expression of N-cadherin. The induced EMT was associated with increased cell motility, invasiveness, and clonogenicity. These progression relevant behaviors were attenuated by treatment with Hh inhibitors cyclopamine and GDC-0449, and after knockdown by Shh-siRNA, and led to reversal of the EMT phenotype. The results with HTB-9 were confirmed using a second bladder cancer cell line, BFTC905 (DM). In a xenograft mouse model TGF-ß1 treated HTB-9 cells exhibited enhanced tumor growth. Although normal bladder epithelial cells could also undergo EMT and upregulate Shh with TGF-ß1 they did not exhibit tumorigenicity. The TGF-ß1 treated HTB-9 xenografts showed strong evidence for a switch to a more stem cell like phenotype, with functional activation of CD133, Sox2, Nanog, and Oct4. The bladder cancer specific stem cell markers CK5 and CK14 were upregulated in the TGF-ß1 treated xenograft tumor samples, while CD44 remained unchanged in both treated and untreated tumors. Immunohistochemical analysis of 22 primary human bladder tumors indicated that Shh expression was positively correlated with tumor grade and stage. Elevated expression of Ki-67, Shh, Gli2, and N-cadherin were observed in the high grade and stage human bladder tumor samples, and conversely, the downregulation of these genes were observed in the low grade and stage tumor samples. Collectively, this study indicates that TGF-ß1-induced Shh may regulate EMT and tumorigenicity in bladder cancer. Our studies reveal that the TGF-ß1 induction of EMT and Shh is cell type context dependent. Thus, targeting the Shh pathway could be clinically beneficial in the ability to reverse the EMT phenotype of tumor cells and potentially inhibit bladder cancer progression and metastasis.

Pulmonary neuroepithelial bodies are polymodal airway sensors: evidence for CO2/H+ sensing.

Pulmonary neuroepithelial bodies (NEB) in mammalian lungs are thought to function as airway O2 sensors that release serotonin (5-HT) in response to hypoxia. Direct evidence that NEB cells also respond to airway hypercapnia/acidosis (CO2/H(+)) is presently lacking. We tested the effects of CO2/H(+) alone or in combination with hypoxia on 5-HT release from intact NEB cells in a neonatal hamster lung slice model. For the detection of 5-HT release we used carbon fiber amperometry. Fluorescence Ca(2+) imaging method was used to assess CO2/H(+)-evoked changes in intracellular Ca(2+). Exposure to 10 and 20% CO2 or pH 6.8-7.2 evoked significant release of 5-HT with a distinct rise in intracellular Ca(2+) in hamster NEBs. This secretory response was dependent on the voltage-gated entry of extracellular Ca(2+). Moreover, the combined effects of hypercapnia and hypoxia were additive. Critically, an inhibitor of carbonic anhydrase (CA), acetazolamide, suppressed CO2/H(+)-mediated 5-HT release. The expression of mRNAs for various CA isotypes, including CAII, was identified in NEB cells from human lung, and protein expression was confirmed by immunohistochemistry using a specific anti-CAII antibody on sections of human and hamster lung. Taken together our findings provide strong evidence for CO2/H(+) sensing by NEB cells and support their role as polymodal airway sensors with as yet to be defined functions under normal and disease conditions.

HMG-CoA reductase mediates the biological effects of retinoic acid on human neuroblastoma cells: lovastatin specifically targets P-glycoprotein-expressing cells.

The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, involved in de novo cholesterol synthesis and cell-cycle progression, was identified as a potential mediator of the growth inhibitory effects of retinoic acid on human neuroblastoma. Lovastatin, a nonreversible inhibitor of HMG-CoA reductase, induced extensive cytotoxicity that was restricted to drug-resistant P-glycoprotein-expressing neuroblastoma cell lines. This response was potentiated by dibutyryl cyclic AMP but not retinoic acid. Patients with advanced-stage metastatic neuroblastoma often display an acquired chemoresistant phenotype, which may in part be mediated by P-glycoprotein. Our studies support the application or use of HMG-CoA reductase inhibitors as potential therapeutic agents in the treatment of these patients who are refractory to chemotherapy.

Decreased levels of the cell-cycle inhibitor p27Kip1 protein: prognostic implications in primary breast cancer.

Breast cancer is the second leading cause of cancer death in North American women. There is considerable need for reliable prognostic markers to assist clinicians in making management decisions. Although a variety of factors have been tested, only tumor stage, grade, size, hormone receptor status, and S-phase fraction are used on a routine basis. The cell cycle is governed by a family of cyclin-dependent kinases (cdks), which are regulated by associated cyclins and by phosphorylation. p27Kip1, a cyclin-dependent kinase inhibitor, regulates progression from G1 into S phase by binding and inhibiting cyclin/cdks. p27Kip1 protein levels and/or activity are upregulated by growth inhibitory cytokines including transforming growth factor-beta (TGF-beta) and, thus, provide an important link between extracellular regulators and the cell cycle. Loss of p27Kip1, a negative cell-cycle regulator, may contribute to oncogenesis and tumor progression. However, p27Kip1 mutations in human tumors are extremely rare. We have demonstrated by immunohistochemistry that p27Kip1 protein levels are reduced in primary breast cancers and that this is associated with tumor progression in both in situ and invasive lesions. This was confirmed by western analysis, reflected in increased G1/S-phase cyclin-dependent kinase activities and shown to be regulated posttranscriptionally by in situ hybridization. Furthermore, on multivariate analysis, low p27Kip1 is a predictor of reduced disease-free survival. This simple and reliable immunohistochemical assay may become a routine part of breast cancer evaluation and may influence patient management.

Glypican-3-deficient mice exhibit developmental overgrowth and some of the abnormalities typical of Simpson-Golabi-Behmel syndrome.

Glypicans are a family of heparan sulfate proteoglycans that are linked to the cell surface through a glycosyl-phosphatidylinositol anchor. One member of this family, glypican-3 (Gpc3), is mutated in patients with the Simpson-Golabi-Behmel syndrome (SGBS). These patients display pre- and postnatal overgrowth, and a varying range of dysmorphisms. The clinical features of SGBS are very similar to the more extensively studied Beckwith-Wiedemann syndrome (BWS). Since BWS has been associated with biallelic expression of insulin-like growth factor II (IGF-II), it has been proposed that GPC3 is a negative regulator of IGF-II. However, there is still no biochemical evidence indicating that GPC3 plays such a role.Here, we report that GPC3-deficient mice exhibit several of the clinical features observed in SGBS patients, including developmental overgrowth, perinatal death, cystic and dyplastic kidneys, and abnormal lung development. A proportion of the mutant mice also display mandibular hypoplasia and an imperforate vagina. In the particular case of the kidney, we demonstrate that there is an early and persistent developmental abnormality of the ureteric bud/collecting system due to increased proliferation of cells in this tissue element. The degree of developmental overgrowth of the GPC3-deficient mice is similar to that of mice deficient in IGF receptor type 2 (IGF2R), a well characterized negative regulator of IGF-II. Unlike the IGF2R-deficient mice, however, the levels of IGF-II in GPC3 knockouts are similar to those of the normal littermates.

Tissue, developmental, and tumor-specific expression of divergent transcripts in Wilms tumor.

The Wilms tumor locus on chromosome 11p13 has been mapped to a region defined by overlapping, tumor-specific deletions. Complementary DNA clones representing transcripts of 2.5 (WIT-1) and 3.5 kb (WIT-2) mapping to this region were isolated from a kidney complementary DNA library. Expression of WIT-1 and WIT-2 was restricted to kidney and spleen. RNase protection revealed divergent transcription of WIT-1 and WIT-2, originating from a DNA region of less than 600 bp. Both transcripts were present at high concentrations in fetal kidney and at much reduced amounts in 5-year-old and adult kidneys. Eleven of 12 Wilms tumors classified as histopathologically heterogeneous exhibited absent or reduced expression of WIT-2, whereas only 4 of 14 histopathologically homogeneous tumors showed reduced expression. These data demonstrate a molecular basis for the pathogenetic heterogeneity in Wilms tumorigenesis.

Wilms tumor locus on 11p13 defined by multiple CpG island-associated transcripts.

Wilms tumor is an embryonal kidney tumor involving complex pathology and genetics. The Wilms tumor locus on chromosome 11p13 is defined by the region of overlap of constitutional and tumor-associated deletions. Chromosome walking and yeast artificial chromosome (YAC) cloning were used to clone and map 850 kilobases of DNA. Nine CpG islands, constituting a "CpG island archipelago," were identified, including three islands that were not apparent by conventional pulsed-field mapping, and thus were at least partially methylated. Three distinct transcriptional units were found closely associated with a CpG island within the boundaries of a homozygous DNA deletion in a Wilms tumor.

Antisense oligonucleotides to Cux-1, a Cut-related homeobox gene, cause increased apoptosis in mouse embryonic kidney cultures.

Cux-1 is a murine homeobox gene that is highly and transiently expressed in the developing kidney. To further evaluate the role of Cux-1 in mammalian kidney development, organotypic cultures of embryonic mouse kidney were incubated with phosphorothioate-coupled antisense Cux-1 oligonucleotides (ODNs) in the presence of cationic liposomes. Inhibition of Cux-1 expression by antisense ODNs was verified by reverse transcription-PCR. Metanephroi that were incubated with antisense Cux-1 ODNs were 23% smaller than metanephroi that were incubated with sense Cux-1 ODNs. Morphologic analysis of metanephroi that were treated with antisense Cux-1 ODNs revealed that ureteric buds and induced epithelial structures were present. However, extensive areas of cell death containing shrunken cells with pyknotic nuclei were also evident. The presence of increased apoptosis was verified by ultrastructural and terminal transferase-mediated dUTP nick end labeling analyses. Two different antisense Cux-1 ODNs targeting either the translation start codon or the homeobox produced increased apoptosis. In contrast, metanephroi incubated with sense ODNs exhibited only occasional apoptotic cells. We conclude that the presence of antisense Cux-1 ODNs does not block nephron induction, but results instead in increased apoptosis. Proper regulation of Cux-1 expression may be necessary for normal kidney development.

Serum sonic hedgehog (SHH) and interleukin-(IL-6) as dual prognostic biomarkers in progressive metastatic breast cancer.

Serum from one hundred and ten breast cancer patients and thirty healthy female volunteers, were prospectively collected and evaluated for serum levels of Shh and IL-6 using human Shh and IL-6 specific enzyme-linked immunoassays. All patients were regularly monitored for event free survival (EFS) and overall survival (OS). Overall outcome analysis was based on serum Shh and IL-6 levels. In patients with progressive metastatic BC, both serum Shh and IL-6 concentrations were elevated in 44% (29 of 65) and 63% (41 of 65) of patients, respectively, at a statistically significant level [Shh (p = 0.0001) and IL-6 (p = 0.0001)] compared to the low levels in healthy volunteers. Serum levels tended to increase with metastatic progression and lymph node positivity. High serum Shh and IL-6 levels were associated with poor EFS and OS opposite to the negative or lower levels in serum Shh and IL-6. The elevated levels of both serum Shh and IL-6 were mainly observed in BC patients who had a significantly higher risk of early recurrence and bone metastasis, and associated with a worse survival for patients with progressive metastatic BC. Further studies are warranted for validating these biomarkers as prognostic tools in a larger patient cohort and in a longer follow-up study.

Relationship of histology of Wilms' tumor to growth characteristics of nude mouse heterotransplants.

Eighteen Wilms' tumors (WIT), including classical triphasic WIT (blastema, tubules, and mesenchyme) and WIT variants (blastema and tubules, monomorphous tubules, multiloculated cysts, rhabdomyomatous WIT, and clear cell sarcoma), were heterotransplanted in nude mice. Ten (56%) tumors grew and were serially passaged. With two exceptions, the histology of the surgically resected tumors and heterotransplants was found to be similar. Tumors showing a prominent blastema component grew rapidly, whereas those with tubular epithelial or mesenchymal differentiation grew more slowly. Tumors injected s.c. consisted almost entirely of blastema, while tumors injected i.p. consisted of blastema with large areas of tubular epithelium. These results demonstrate that nude mouse heterotransplants of WIT closely resemble the surgically resected tumors from which they derive, that growth rates of WIT heterotransplants depend on the identity of the tumor cells, and that differentiation of WIT heterotransplants can be modulated, depending on the route of administration of tumor cells.

Histochemical and immunohistochemical characterization of surgically resected and heterotransplanted Wilms' tumor.

Nine surgically resected Wilms' tumors (WIT) and nude mouse heterotransplants from one WIT were studied by histochemistry and immunohistochemistry. Histochemistry showed acid phosphatase in all cells, while alkaline phosphatase and gamma-glutamyl transpeptidase were present in only some tubules. Using immunohistochemistry, antibodies to the intermediate filaments cytokeratin and vimentin distinguished tubular epithelium and mesenchyme, respectively. WIT tubules were also identified using antibody against a structural component (epithelial membrane antigen) and a secretory product (uromucoid) associated with distal convoluted tubules of normal kidney. Basement membrane surrounding the tubules of WIT was demonstrated using antibody to type IV collagen plus laminin. Different blastema subpopulations were negative or stained positively with antibodies to cytokeratin and vimentin. Production of basement membrane by blastema was also shown. Fetal antigen expression in WIT was examined using the monoclonal PI 153/3 and J5 antibodies. The blastema and tubules of WIT were strongly stained by PI 153/3, which did not label normal adult kidney, and weakly stained by J5, which strongly labeled glomeruli and proximal convoluted tubules of normal kidney. These studies show that WIT blastema is heterogeneous in intermediate filament subtypes, while WIT tubules more closely resemble distal than proximal convoluted tubules of adult kidneys but also retain expression of fetal antigens.

Enhancement by retinoic acid and dibutyryl cyclic adenosine 3':5'-monophosphate of the differentiation and gene expression of human neuroblastoma cells induced by interferon.

Human neuroblastoma cell lines are induced to differentiate and display neuronal phenotypes when treated with interferon (IFN)-alpha 2, retinoic acid (RA), or dibutyryl cyclic AMP (dbcAMP). We investigated the effects of combinations of these agents in induction-differentiation in the neuroblastoma cell line, NUB-6. The inductive effect of IFN-alpha 2 was markedly enhanced when used in combination with RA or dbcAMP. In parallel, RA or dbcAMP also enhanced the level of 2'-5'-oligoadenylate (2-5A) synthetase, and enzyme induced by IFNs and implicated in their biological action. The levels of another IFN-inducible enzyme, p68 kinase, were not enhanced by the combination treatments. The enhancement effects appeared to be exerted largely at the posttranscriptional level as both RA and dbcAMP stabilized IFN-induced 2-5A synthetase mRNA, resulting in increased enzyme activity. Thus, the 2-5A synthetase system is likely involved in mediating the IFN-alpha 2-induced differentiation of neuroblastoma cells and may also mediate the enhancement effects of RA and dbcAMP on IFN activity in these cells. These results also provide a rational basis for establishing a combination therapeutic approach for the treatment of neuroblastoma.

Importance of phenotypic and molecular characterization for identification of a neuroepithelioma tumor cell line, NUB-20.

A neuroblastic-like cell line (NUB-20) was derived from a case of histopathologically diagnosed metastatic neuroblastoma. The metastatic tumor and nude mouse heterotransplant resembled neuroblastoma by histological criteria, in contrast to the primary tumor, which was differentially classified as Ewing's sarcoma. However, the cell line demonstrated a unique phenotype in culture with respect to morphology, immunohistochemical markers, and sensitivity to a battery of differentiation modulators. These characteristics, together with the presence of a chromosomal translocation (11;22),(q24;q12) and amplification with enhanced expression of the c-myc protooncogene rather than N-myc, established this tumor as neuroepithelioma. Neuroepithelioma is a tumor type distinct from, but related to, neuroblastoma in its development from the neural crest lineage. These results emphasize the growing importance of cytogenetic and molecular markers in the classification and characterization of human tumors.

Mutations of the p53 tumor suppressor gene occur infrequently in Wilms' tumor.

Mutations of the p53 tumor suppressor gene occur frequently in a variety of adult-onset tumors, including colon, breast, lung, and brain, yet are infrequently identified in pediatric malignancies. Wilms' tumor, a common solid tumor of childhood, can be associated with mutations of the WT1 gene. Alterations of the p53 gene have been shown to modulate the ability of WT1 to transactivate its targets. Although positive p53 immunostaining has been demonstrated in Wilms' tumors, the correlation to p53 gene mutations is not clear. We examined Wilms' tumor samples for p53 mutations utilizing polymerase chain reaction-single-strand conformation polymorphism analysis and single-strand DNA sequencing. Mutations in the coding region of the p53 gene were demonstrated in 2 of 21 (9.5%) Wilms' tumors. Each mutation yielded a substitution of amino acid residues. One mutation was located in exon 6 and the other in exon 7. Both mutations were found in tumors from patients with advanced stage disease. Focal anaplasia was demonstrated in one of these tumors. Our data suggest that although p53 mutations occur infrequently in Wilms' tumor, they may be associated with advanced disease.

Monoclonal antibodies to an epithelial ovarian adenocarcinoma: distinctive reactivity with xenografts of the original tumor and a cultured cell line.

Four monoclonal antibodies (mAb) (8C, 10B, M2A, and M2D) were produced against the human epithelial ovarian adenocarcinoma cell line, HEY. The affinity constants of binding of the mAb to cultured HEY cells were 8 X 10(8) M-1 (M2D) and 10(9) M-1 (8C and 10B). mAb 8C reacted with a major glycoprotein of Mr 90,000 on the surface of HEY cells. The four mAb differed from previously reported mAb to epithelial ovarian adenocarcinomas on the basis of their reactivity with cultured ovarian adenocarcinoma cell lines using a cell-binding radioimmunoassay, and their staining of cryostat sections of various human normal and tumor tissues using an immunoperoxidase reaction. All four mAb reacted with s.c. tumors derived by injecting cultured HEY cells into thymectomized CBA/CJ mice. However, only two of the four mAb (8C and 10B) also reacted with s.c. tumors of the original HEY xenograft from which the cultured cell line was derived. In addition, mAb 8C and 10B reacted by immunoperoxidase staining with 2 and 4 different cases, respectively, of 11 epithelial ovarian adenocarcinomas examined. Cultured HEY cells were adapted to grow i.p. in BALB/c-nu/nu mice and the i.p. tumors retained their reactivity with the monoclonal antibodies. These tumor-bearing mice offer a useful model system for studying the potential of mAb, especially 8C and 10B, for the diagnosis and treatment of patients with peritoneal extension of epithelial ovarian adenocarcinomas.

Simultaneous Targeting of Bladder Tumor Growth, Survival, and Epithelial-to-Mesenchymal Transition with a Novel Therapeutic Combination of Acetazolamide (AZ) and Sulforaphane (SFN).

BACKGROUND: Current chemotherapies for advanced stage metastatic bladder cancer often result in severe side effects, and most patients become drug resistant over time. Thus, there is a need for more effective therapies with minimal side effects. OBJECTIVE: The acid/base balance in tumor cells is essential for tumor cell functioning. We reasoned that simultaneous targeting of pH homeostasis and survival pathways would improve therapeutic efficacy. We evaluated the effectiveness of targeting pH homeostasis with the carbonic anhydrase inhibitor acetazolamide (AZ) in combination with the survival pathway targeting isothiocyanate sulforaphane (SFN) on the HTB-9 and RT112(H) human bladder tumor cell lines. MATERIALS AND METHODS: We assessed viability, proliferation, and survival in vitro and effect on xenografts in vivo. RESULTS: Combination AZ + SFN treatment induced dose-dependent suppression of growth, produced a potent anti-proliferative and anti-clonogenic effect, and induced apoptosis through caspase-3 and PARP activation. The anti-proliferative effect was corroborated by significant reductions in Ki-67, pHH3, cyclin D1, and sustained induction of the cell cycle inhibitors, p21 and p27. Both active p-Akt (Ser473) and p-S6 were significantly downregulated in the AZ + SFN combination treated cells with a concomitant inhibition of Akt kinase activity. The inhibitory effects of the AZ + SFN combination treatment showed similar efficacy as the dual PI3K/mTOR pathway inhibitor NVP-BEZ235, albeit at an expected higher dose. In terms of the effect on the metastatic potential of these bladder cancers, we found downregulated expression of carbonic anhydrase 9 (CA9) concomitant with reductions in both E-cadherin, N-cadherin, and vimentin proteins mitigating the epithelial-to-mesenchymal transition (EMT), suggesting negation of this program. CONCLUSION: We suggest that reductions in these components could be linked with downregulation of the survival mediated Akt pathway and suggested an active role of the Akt pathway in bladder cancer. Altogether, our in vitro and pre-clinical model data support the potential use of an AZ + SFN combination for the treatment of bladder cancer.

Overexpression of sonic hedgehog in the triple negative breast cancer: clinicopathological characteristics of high burden breast cancer patients from Bangladesh.

Dysregulation of Hedgehog (Hh) signaling pathway has been documented in mammary gland development and breast cancer (BC) progression. Despite the remarkable progress in therapeutic interventions, BC related mortality in Bangladesh increased in the last decade. Triple negative breast cancer (TNBC) still presents a critical therapeutic challenge. Thus effective targeted therapy is urgently needed. In this study, we report the clinicopathological characteristics and prognosis of BC patients from Bangladesh. Routine immunohistochemical analysis and high throughput RNA-Seq data from the TCGA library were used to analyze the expression pattern and association of high and low level of Shh expression in a collection of BC patients with a long-term follow-up. High levels of Shh were observed in a subset of BC tumors with poor prognostic pathological features. Higher level of Shh expression correlated with a significantly poorer overall survival of patients compared with patients whose tumors expressed a low level of Shh. These data support the contention that Shh could be a novel biomarker for breast cancer that is involved in mediating the aggressive phenotype of BC. We propose that BC patients exhibiting a higher level of Shh expression, representing a subset of BC patients, would be amenable to Shh targeted therapy.

Loss of heterozygosity at chromosome 11p15 in Wilms tumors: identification of two independent regions.

Loss of heterozygosity (LOH) on the short arm of chromosome 11 is the most frequent genetic alteration in Wilms tumors, indicating that one or more tumor suppressor genes that map to this chromosomal region are involved in the development of the disease. The WT1 gene located on 11p13 has been characterized but mutations in this gene occur in only about 10% of Wilms tumors. A second locus (WT2) at chromosome 11p15 has also been described in Wilms tumors but thus far efforts to clone the WT2 gene(s) have been frustrated by the large size (approximately 10 Mb) of this region. Using a high-density marker LOH analysis of 11p15.5-15.4, we have refined the location of a Wilms tumor suppressor gene between the markers D11S1318-D11S1288 (approximately 800 kb) within 11p15.5. We have also identified a second, novel region of LOH that spans the markers D11S1338-D11S1323 (approximately 336 kb) at 11p15.5-p115.4. Thus a second distinct locus, in addition to the previously defined WT2, on chromosome 11p15.5, appears to play a role in the development of Wilms tumors.

Amplification of N-myc and ornithine decarboxylase genes in human neuroblastoma and hydroxyurea-resistant hamster cell lines.

The genes for the M2 subunit of ribonucleotide reductase (RRM2), ornithine decarboxylase (ODC1), and 55,000-Daltons protein (P5), are amplified in hydroxyurea-resistant hamster and human cell lines. These genomic sequences have been mapped to hamster chromosome 7 and to human chromosome 2p24-25 near the cytogenetic location of the N-myc gene. We now report that genomic sequences homologous to N-myc are amplified in hydroxyurea-resistant hamster lung cell line, 600H, and the N-myc gene segregates with hamster chromosome 7 in mouse-hamster somatic cell hybrids. The conserved linkage group consisting of the RRM2, ODC1, P5, and N-myc in the hamster and human genomes prompted our investigation of human neuroblastomas. We report here that genomic DNA from 1 of 6 primary neuroblastoma tumors containing amplified N-myc also contains amplified sequences homologous to a hamster ODC cDNA.

Regulation of renal sulfoglycolipid biosynthesis.

The in vitro activity of the renal galactolipid sulfotransferase and the level of sulfated glycolipids in the rat kidney have been correlated as a function of age. The galactolipid sulfotransferase was found to be greatly reduced in the young as compared with the adult animal. The relatively minor changes in the sulfated glycolipid content of the kidney with age suggests that an increase in sulfoglycolipid turnover occurs during growth. An inhibitory activity was detected in the homogenate supernate of the young animal capable of reducing the in vitro sulfotransferase activity of the adult. Assay of the human renal galactolipid sulfotransferase showed that this enzyme activity is deleted in samples of the blastematous form of Wilm's renal tumor. The results suggest that the rate of synthesis of renal sulfoglycolipids may prove a marker of renal development, perhaps by post translational regulation.