Zinc‑finger protein 750 mitigates malignant biological behavior of oral CSC‑like cells enriched from parental CAL‑27 cells

Abstract

Oral squamous cell carcinoma (OSCC) is the most commonly occurring oral malignancy. Cancer stem cells (CSCs) are known to be responsible for cancer recurrence and metastasis. Zinc-finger protein 750 (ZNF750) has been reported to inhibit OSCC cell proliferation and invasion. The present study aimed to elucidate the role of ZNF750 in the inhibition of the renewal ability of CSCs derived from the OSCC cell line, CAL-27. The effects of ZNF750 on CSC-like properties were examined using aldehyde dehydrogenase (ALDH), tumor sphere formation and colony formation assays. Reverse transcription-quantitative PCR and western blotting were performed to detect the expression levels of octamer-binding transcription factor 4, sex-determining region Y-box 2, the enhancer of zeste homolog 2 (Ezh2), embryonic ectoderm development (EED) and SUZ12 polycomb repressive complex 2 subunit (SUZ12), and for the identification of genes associated with metastasis. ZNF750 effectively attenuated CSC-like cell self-renewal abilities; ZNF750 decreased the ALDH-positive cell population, tumor sphere and colony formation abilities, cell viability and stemness factors. Furthermore, the expression levels of Ezh2, EED and SUZ12 were decreased by ZNF750. ZNF750 inhibited MMP1, 3, 9 and 13 expression levels, and decreased the cell invasion and migratory abilities. Moreover, the expression of tissue inhibitors of matrix metalloproteinases-1 was increased by ZNF750. However, opposite effects were observed following the knockdown of the ZNF750 gene. Overall, the present study demonstrated that ZNF750 has the potential to inhibit the renewal of CSC-like cells enriched from parental CAL-27 cells.

NMR structure verifies the eponymous degenerate zinc finger domain of transcription factor ZNF750

“…The names in parentheses are the Bruker pulse programs for the experiments. Experiments on the D2O sample included 50 and 200 ms mixing time NOESY, DQF-COSY (cosydfph), ECOSY (ecos3nph), and natural abundance 13 C-HSQC (hsqcetgpsi2). Most of the assignments were obtained from a sequential walk using the NOESY and TOCSY spectra recorded in H2O (Fig.…”

“…Experiments in D2O were used for aromatic assignments, and to observe Ha resonances without interference from solvent. The extent of assigned resonances was 1 H (93%), 13 C (83%, excluding C'), and 15 N (77%). Stereospecific assignments were obtained from ECOSY and short mixing time (50 ms) NOESY experiments (69).…”

“…Distance restraints were obtained from NOESY crosspeak intensities calculated with the program CcpNmr Analysis 2.5 (70). Torsional restraints were calculated from 1 HN, 1 Ha 13 Ca, 13 Cb, and 15 N chemical shifts using the program TALOS-N (71). An initial set of 20 lowest energy structures without violations was calculated from a starting set of 100 random conformation with the program XPLOR-NIH (72) to identify the Zn 2+ ligands.…”

“…Over the last few years it has become evident that in addition to skin differentiation ZNF750 has roles in oral (13) and esophageal (14) squamous cell carcinoma, melanoma (15), ocular sebaceous carcinoma (16), prostate (17) and breast cancers (18)(19)(20). A common mechanistic theme linking the involvement of ZNF750 in pathologies as varied as skin disease and cancers is that the transcription factor regulates cell differentiation.…”

“…A common mechanistic theme linking the involvement of ZNF750 in pathologies as varied as skin disease and cancers is that the transcription factor regulates cell differentiation. ZNF750 appears to act as a tumor suppressor by inhibiting cancer stem cells, and has additional roles in regulating tumor growth, cell migration, and adhesion (13). When ZNF750 is mutated or expressed at low levels, it no longer acts as a tumor suppressor and cancer cells proliferate (21).…”