Secretagogin Is a Novel Marker for Neuroendocrine Differentiation

Birkenkamp‐Demtröder, Karin; Wagner, Ludwig; Sørensen, Flemming Brandt; Astrup, Lærke Boye; Gärtner, Wolfgang; Scherübl, Hans; Heine, Bernhard; Christiansen, Peer; Ørntoft, Torben F.

doi:10.1159/000091207

Cited by 51 publications

(57 citation statements)

References 46 publications

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“…Immunohistochemistry-IHC was performed as described previously (20). In brief, paraffin was removed followed by blocking of endogenous peroxidase activity, heat-induced epitope demasking, and blocking to prevent unspecific binding.…”

Section: Methodsmentioning

confidence: 99%

“…After deparaffinization, sections were incubated with a mixture of CLU H-330 rabbit polyclonal antibody (1:50 dilution) and monoclonal mouse anti-human CgA antibody (1:10 dilution). CgA is a well known marker of neuroendocrine differentiation (20). Bound primary antibodies were detected with AlexaFluor 488-conjugated goat anti-rabbit IgG highly crossadsorbed (1:1,000; Molecular Probes Inc., Eugene, OR) and AlexaFluor 546-conjugated goat anti-mouse IgG1 (1:400; Molecular Probes Inc.).…”

Section: Methodsmentioning

confidence: 99%

“…Western Blotting-Western blot analysis was performed as described previously (20). From eight pairs of adenocarcinoma and adjacent normal mucosa 10 g of total protein were loaded on 12% NuPAGE gels (Invitrogen) and blotted to PVDF-plus membranes.…”

Section: Methodsmentioning

confidence: 99%

“…To test this hypothesis, we performed IHC with CLU and CgA, an often used marker of neuroendocrine differentiation (20), on consecutive sections of normal colon mucosa specimens from two individuals (Fig. 3, A and B).…”

Section: Clu Protein Expression In Normal Mucosa: Only a Small Fractimentioning

confidence: 99%

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Clusterin Expression in Normal Mucosa and Colorectal Cancer

Andersen

Schepeler

Thorsen

et al. 2007

Molecular & Cellular Proteomics

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The gene Clusterin is a target for cancer therapy in clinical trials. The indication for intervention is up-regulated Clusterin expression. Clusterin has been reported to be deregulated in multiple cancer types, including colorectal cancer (CRC). However, for CRC the studies have disagreed on whether Clusterin is up-or down-regulated by neoplastic cells. In the present study we sought to clarify the expression and distribution of Clusterin mRNAs and proteins in normal and neoplastic colorectal tissue through laser microdissection, variant-specific real time RT-PCR, immunohistochemistry, immunofluorescence, Western blotting, and array-based transcriptional profiling. At the transcript level we demonstrated the expression of two novel Clusterin transcripts in addition to the known transcript, and at the protein level we demonstrated two Clusterin isoforms. Our analysis of normal epithelial cells revealed that among these, Clusterin was only expressed by rare neuroendocrine subtype. Furthermore our analysis showed that in the normal mucosa the majority of the observed Clusterin protein originated from the stromal compartment. In tumors we found that Clusterin was de novo synthesized by non-neuroendocrine cancer cells in ϳ25% of cases. Moreover we found that the overall Clusterin level in tumors often appeared to be lower than in normal mucosa due to the stromal compartment often being suppressed in tumors. Although Clusterin in normal neuroendocrine cells showed a basal localization, the localization in cancer cells was often apical and in some cases associated with apical secretion. Collectively our results indicate that Clusterin expression is very complex.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Clu Protein Expression In Normal Mucosa: Only a Small Fractimentioning

confidence: 99%

See 2 more Smart Citations

Clusterin Expression in Normal Mucosa and Colorectal Cancer

Andersen

Schepeler

Thorsen

et al. 2007

Molecular & Cellular Proteomics

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“…20, except that citrate buffer (10 nM, pH 6.0) was used for FYN epitope demasking. Antibodies against FYN (clone 25, BD Transduction Laboratories) and high-molecular-weight cytokeratin (HMW-ck; Dakocytomation) were diluted 1:10 and 1:50 in TBS (50 mM Tris; 0.9% NaCl, pH 7.6) with 1% BSA.…”

Section: Immunohistochemistrymentioning

confidence: 99%

Chromosomal deletion, promoter hypermethylation and downregulation of FYN in prostate cancer

Sørensen¹,

Borre²,

Ørntoft³

et al. 2007

Intl Journal of Cancer

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Loss of heterozygosity (LOH) at 6q is a frequent chromosomal aberration in prostate adenocarcinoma; however, a possible target gene remains to be identified. Key words: prostate cancer; FYN tyrosine kinase; tumor suppressor gene; hypermethylation; loss of heterozygosity Development and progression of prostate cancer is associated with the accumulation of complex genetic and epigenetic aberrations.1 Recently, we identified common allelic imbalance at 6q14-6q22 in prostate cancer by a genome-wide loss of heterozygosity (LOH) analysis using high-density single nucleotide polymorphism (SNP) microarrays.2 Other groups have earlier reported similar regions of deletion/LOH at 6q in prostate cancer (Ref. 3 and references therein); however, a possible target tumor suppressor gene (TSG) remains to be identified from this region. Interestingly, several cancer types, including breast, 4 gastric 5 and cervical cancer 6 as well as a variety of hematopoietic malignancies 7,8 have common regions of deletion at 6q that coincide with that identified in prostate cancer, suggesting that a putative target TSG at 6q may be shared by at least some of these malignancies.Retroviral tagging has proved to be a powerful cancer gene discovery tool, with many genes identified as common integration sites in retrovirus-induced murine leukemia/lymphoma models, playing critical roles also in human cancers, including solid tumors.9,10 On the basis of this and substantiated by the overlapping deletions at 6q found in both prostate cancer and various types of human hematopoietic malignancies, we envisaged that retroviral tags from murine leukemia/lymphoma models might help the search for a candidate TSG at 6q. Hence, in this study, to identify a new possible TSG in prostate cancer, we hypothesized that a gene in the main LOH region at 6q14-6q22 that is both (i) transcriptionally downregulated in prostate cancer compared to nonmalignant prostate tissues and (ii) disrupted by retroviral insertion in murine hematopoietic cancer models, would provide a good candidate for further analysis. Accordingly, the SRC family tyrosine kinase gene FYN at 6q21 was selected for further investigation.FYN contains an N-terminal SH4 myristoylation and palmitoylation domain, which targets the protein to the inner plasma membrane. It is followed by a unique sequence, distinguishing FYN from other SRC family members, 2 protein-protein interaction domains (SH3 and SH2), a kinase domain (SH1) and a C-terminal negative regulatory domain.11 The 2 known major splice forms, FYN(B) (aka P59FynB) using exon 7A and FYN(T) (aka P59FynT) using exon 7B, 11 differ in a linker region between SH2 and SH1 that extends into the kinase domain, causing moderate regulatory differences between these isoforms.12 FYN(B) is highly expressed in brain, and hematopoietic cells express mainly FYN(T), while most other tissues express both isoforms.11 A variant mRNA lacking exon 7 (FYN(D7)) exists in blood cells, but the corresponding endogenous protein has not been documented. 13The biological fun...

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Calcium‐binding proteins typify the dopaminergic neuronal subtypes in the ventral tegmental area of zebra finch,Taeniopygia guttata

Mitra

Basu

Singh

et al. 2022

J of Comparative Neurology

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Calcium-binding proteins (CBPs) regulate neuronal function in midbrain dopamine (DA)-ergic neurons in mammals by buffering and sensing the intracellular Ca 2+ , and vesicular release. In birds, the equivalent set of neurons are important in song learning, directed singing, courtship, and energy balance, yet the status of CBPs in these neurons is unknown. Herein, for the first time, we probe the nature of CBPs, namely, Calbindin-, Calretinin-, Parvalbumin-, and Secretagogin-expressing DA neurons in the ventral tegmental area (VTA) and substantia nigra (SN) in the midbrain of zebra finch, Taeniopygia guttata. qRT-PCR analysis of ventral midbrain tissue fragment revealed higher Calbindin-and Calretinin-mRNA levels compared to Parvalbumin and Secretagogin. Application of immunofluorescence showed CBP-immunoreactive (-i) neurons in VTA (anterior [VTAa], mid [VTAm], caudal [VTAc]), SN (compacta [SNc], and reticulata [SNr]). Compared to VTAa, higher Calbindin-and Parvalbumin-immunoreactivity (-ir), and lower Calretinin-ir were observed in VTAm and VTAc. Secretagogin-ir was highly localized to VTAa. In SN, Calbindin-and Calretinin-ir were higher in SNc, SNr was Parvalbumin enriched, and Secretagogin-ir was not detected. Weak, moderate, and intense tyrosine hydroxylase (TH)-i VTA neurons were demarcated as subtypes 1, 2, and 3, respectively. While subtype 1 TH-i neurons were neither Calbindin-nor Calretinin-i, ∼80 and ∼65% subtype 2 and ∼30 and ∼45% subtype 3 TH-i neurons co-expressed Calbindin and Calretinin, respectively. All TH-i neuronal subtypes coexpressed Parvalbumin with reciprocal relationship with TH-ir. We suggest that the CBPs may determine VTA DA neuronal heterogeneity and differentially regulate their activity in T. guttata.

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Secretagogin Is a Novel Marker for Neuroendocrine Differentiation

Cited by 51 publications

References 46 publications

Clusterin Expression in Normal Mucosa and Colorectal Cancer

Clusterin Expression in Normal Mucosa and Colorectal Cancer

Chromosomal deletion, promoter hypermethylation and downregulation of FYN in prostate cancer

Calcium‐binding proteins typify the dopaminergic neuronal subtypes in the ventral tegmental area of zebra finch,Taeniopygia guttata

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