A novel antibody against cancer stem cell biomarker, DCLK1-S, is potentially useful for assessing colon cancer risk after screening colonoscopy

DCLK1 expression is critically required for maintaining growth of human colon cancer cells (hCCCs). Human colorectal tumors (CRCs) and hCCCs express a novel short isoform of DCLK1 (DCLK1-S; isoform 2) from β-promoter of hDCLK1 gene, while normal colons express long isoform (DCLK1-L; isoform 1) from 5'(α)-promoter, suggesting that DCLK1-S, and not DCLK1-L, marks cancer stem cells (CSCs). Even though DCLK1-S differs from DCLK1-L by only six amino acids, we succeeded in generating a monospecific DCLK1-S-Antibody (PS41014), which does not cross-react with DCLK1-L, and specifically detects CSCs. Subcellular localization of S/L-isoforms was examined by immune-electron-microscopy (IEM). Surprisingly, besides plasma membrane and cytosolic fractions, S/L also localized to nuclear/mitochondrial fractions, with pronounced localization of S-isoform in the nuclei and mitochondria. Sporadic CRCs develop from adenomas. Screening colonoscopy is used for detection/resection of growths, and morphological/pathological criteria are used for risk assessment and recommendations for follow-up colonoscopy. But, these features are not precise and majority of the patients will never develop cancer. We hypothesized that antibody-based assay(s), which identify CSCs, will significantly improve prognostic value of morphological/pathological criteria. We conducted a pilot retrospective study with PS41014-Ab, by staining archived adenoma specimens from patients who developed (high-risk), or did not develop (low-risk) adenocarcinomas within 10-15 years. PS41014-Ab stained adenomas from initial and follow-up colonoscopies of high-risk patients, at significantly higher levels (three to fivefold) than adenomas from low-risk patients, suggesting that PS41014-Ab could be used as an additional tool for assessing CRC risk. CRC patients, with high DCLK1-S-expressing tumors (by qRT-PCR), were reported to have worse overall survival than low expressers. We now report that DCLK1-S-specific Ab may help to identify high-risk patients at the time of index/screening colonoscopy.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:97

Enthalten in:

Laboratory investigation; a journal of technical methods and pathology - 97(2017), 10 vom: 17. Okt., Seite 1245-1261

Sprache:

Englisch

Beteiligte Personen:

Sarkar, Shubhashish [VerfasserIn]
Popov, Vsevolod L [VerfasserIn]
O'Connell, Malaney R [VerfasserIn]
Stevenson, Heather L [VerfasserIn]
Lee, Brian S [VerfasserIn]
Obeid, Robert A [VerfasserIn]
Luthra, Gurinder K [VerfasserIn]
Singh, Pomila [VerfasserIn]

Links:

Volltext

Themen:

Antibodies
Biomarkers, Tumor
DCLK1 protein, human
Doublecortin-Like Kinases
EC 2.7.1.11
EC 2.7.11.1
Intracellular Signaling Peptides and Proteins
Journal Article
Protein Isoforms
Protein Serine-Threonine Kinases

Anmerkungen:

Date Completed 11.10.2017

Date Revised 16.02.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1038/labinvest.2017.40

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM271014806