Correlation of Cancer Stem-Cell Markers OCT4, SOX2, and NANOG with Clinicopathological Features and Prognosis in Operative Patients with Rectal Cancer

PURPOSE: To investigate the association of cancer stem-cell markers [octamer-binding transcription factor 4 (OCT4), sex determining region Y-box 2 (SOX2), and Nanog homebox (NANOG)] expression with clinicopathological properties and overall survival (OS) in operative rectal cancer (RC) patients receiving adjuvant therapy. MATERIALS AND METHODS: 153 patients with primary RC receiving surgery were enrolled. Tumor tissue and paired adjacent normal tissue sample were collected, and OCT4, SOX2, and NANOG expressions were assessed by immunofluorescent staining. The median follow-up duration was 5.2 years, and the last follow-up date was August 2016. RESULTS: Tumor tissue OCT4 (p < 0.001), SOX2 (p=0.003), and NANOG (p < 0.001) expressions were higher than those in adjacent tissue. OCT4 expression was positively correlated with pathological grade (R=0.185, p=0.022), tumor size (R=0.224, p=0.005), and N stage (R=0.170, p=0.036). NANOG expression was positively associated with tumor size (R=0.169, p=0.036). Kaplan-Meier suggested that OCT4+ was associated with worse OS compared with OCT4− (p < 0.001), while no association of SOX2 (p=0.121) and NANOG expressions (p=0.195) with OS was uncovered. Compared with one or no positive marker, at least two positive markers were associated with shorter OS (p < 0.001), while all three positive markers were correlated with worse OS compared with two or less positive markers (p < 0.001). Multivariate Cox's analysis revealed that OCT4+ (p < 0.001) and N stage (p=0.046) were independent factors for shorter OS. CONCLUSION: Tumor tissue OCT4 expression was correlated with poor differentiation, tumor size, and N stage, and it can serve as an independent prognostic biomarker in operative patients with RC receiving adjuvant therapy.

Isolation of breast cancer stem cell from MDA-MB231 cell line using vincristine / Aislamiento de células madre de cáncer de mama de la línea celular MDA-MB231 utilizando vincristina

Cancer has been considered as a stem cell disease. Suspension culture combined with anti-cancer drugs has recently been proposed for isolation of cancer stem cells (CSCs). In the current study, Vincristine as an anti-cancer drug combined with suspension culture was used for isolation and purification of CSCs from human breast cancer cell line (MDA-MB231). The cells were treated with different concentrations of vincristine (0, 2, 4, 6 and 8 ng/ml). Stem cells were identified with the expression of OCT4, nanog, SOX2 and nucleostemin genes by RT-PCR. Mammosphere forming unit was measured upon suspension culture containing EGF, bFGF, LIF, B27, insulin and BSA. The isolated mammospheres were investigated for CD44 expression. Results showed that 4 ng/ml of vincristine for 72 hours could be utilized as the best and most reliable dose which eliminates around 80 % of non-cancer stem cells with no destructive effect on CSCs' viability (P> 0.05). RT-PCR demonstrated that drug treated cells expressed OCT4, nanog, SOX2 and nucleostemin. Mammosphere formation unit of cells pretreated with vincristine was significantly higher than unpretreated ones (P>0.05). Immunofluorescence staining for CD44 depicted high expression of CSC marker among the isolated mammospheres. Vincristine combined with suspension culture can be considered as an appropriate method to isolate CSC.

El cáncer ha sido considerado como una enfermedad de células madre. Recientemente se ha propuesto cultivo en suspensión en combinación con medicamentos contra el cáncer para aislamiento de las células madre del cáncer (CMC). En este estudio se utilizó la vincristina como fármaco anticanceroso combinado con cultivo en suspensión para el aislamiento y purificación de las células madre cancerosas, de la línea celular de cáncer de mama humano (MDA-MB231). Las células se trataron con diferentes concentraciones de vincristina (0, 2, 4, 6 y 8 ng/ml). Las células madre se identificaron mediante la expresión de los genes OCT4, Nanog, SOX2 y nucleostemin por RT-PCR. La unidad de formación mammosphere se midió a través de cultivo en suspensión que contenía EGF, bFGF, LIF, B27, insulina y BSA. Los mammospheres aislados fueron estudiados para la expresión de CD44. Los resultados mostraron que 4 ng/ml de vincristina durante 72 horas podrían ser utilizados como la mejor y más fiable dosis que permite eliminar alrededor del 80 % de las células madre no cancerosas, sin causar un efecto destructivo sobre la viabilidad de las CMC (P> 0,05). La RT-PCR mostró que en las células tratadas con él fármaco hubo expresión de los genes OCT4, Nanog, SOX2 y nucleostemin. La unidad de formación de las células pretratadas con vincristina fue significativamente más alta que las unidades sin tratamiento previo (P>0,05). La inmunofluorescencia para CD44 muestró una alta expresión del marcador de CMC entre mammospheres aisladas. La vincristina en combinación con el cultivo en suspensión puede ser considerado como un método apropiado para aislar CMC.

Sonic hedgehog inhibition induces mouse embryonic stem cells to differentiate toward definitive endoderm.

In the experimental group (shh inhibited group), there were significant decreases in the expression of Oct4, Nanog, Shh, GATA4, Brachyury and Goosecoid, while increases were observed for TAT and Pdx1. The expression of Sox17 did not differ between two control and experimental groups. In experimental group, the amount of GSC positive cells was somehow lower but it seems that there was no difference for Sox17. Shh inhibition induces ESCs to differentiate toward definitive endoderm by committing mesendodermal lineages.

Stemness Evaluation of Mesenchymal Stem Cells from Placentas According to Developmental Stage: Comparison to Those from Adult Bone Marrow

This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (P<0.001, 31.7+/-5.8 vs. 15.7+/-6.2 with group I, 9.2+/-4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs.

OCT4 expression on a case of poorly differentiated (insular) carcinoma of the thyroid gland and minireview.

Poorly differentiated (insular) carcinoma of the thyroid gland is rare and defined as follicular-cell neoplasms that show limited evidence of structural follicular cell differentiation and occupy both morphologically and behaviourally an intermediate position between differentiated (follicular and papillary carcinomas) and undifferentiated (anaplastic) carcinomas. The authors report a case of a 37-year-old Thai woman who presented with a prolonged left thyroid nodule. Final pathological diagnoses of her mass were poorly differentiated (insular) carcinoma with lymphovascular invasion and nodular goiter. The tumor cell arrangements were nest (insular) and trabecular patterns with some follicular formations. Immunohistochemistry of the tumor cells revealed negative immunostaining for OCT4. Expression of OCT4 gene is involved in the regulation and maintenance of pluripotency of embryonic stem cells, germ cells, and in tumor cells. The authors believe that poorly differentiated (insular) carcinoma of the thyroid gland probably develops from the remnant of thyroid stem cells and is not associated with dedifferentiation (anaplasia or loss of cellular differentiation) from nodular goiter or cells of other thyroid carcinomas. Although there was negative immunostain for OCT4 in the presented case, the authors assumed that the tumor cells behave with an intermediate position between thyroid stem cells and prothyrocytes Also they do not behave with thyroblasts. Additionally, the tumor may be associated with new cellular dedifferentiation. However, there is only one case of immunohistochemistry of OCT4 in poorly differentiated (insular) carcinoma of the thyroid gland. Thus, prognosis of the presented still is mainly correlated with clinical and histological findings. Further research on expression of OCT4 gene on thyroid cancers and other malignant tumors relating to tumorigenic cancer cells (cancer stem cells) may be useful to prognostic evaluation and administration of a new chemotherapy and/or radiotherapy that is specific for tumor-initiating cells.