In vitro anti-leukemic effect of Wharton's jelly derived mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) have the ability to self-renew and are multi-potent. They are a primary candidate for cell-based therapy due to their potential anti-cancer effects. The aim of this study was to evaluate the in vitro anti-leukemic effect of Wharton's Jelly-derived MSC (WJ-MSC) on the leukemic cell lines K562 and HL-60. METHODS: In this present study, WJ-MSCs were isolated from human umbilical cord. The cells were incubated according to the standard culture conditions and characterized by flow cytometry. For experiments, WJ-MSC and leukemic cells were incubated in the direct co-culture at a ratio of 1:5 (leukemia cells: WJ-MSC). HUVEC cells were used as a non-cancerous cell line model. The apoptotic effect of WJ-MSCs on the cell lines was analyzed using Annexin V/PI apoptosis assay. RESULTS: After the direct co-culture of WJ-MSCs on leukemic cell lines, we observed anti-leukemic effects by inducing apoptosis. We had two groups of determination apoptosis with and without WJ-MSCs for all cell lines. Increased apoptosis rates were observed in K562 and HL-60 cell lines, whereas the apoptosis rates in HUVEC cells were low. CONCLUSIONS: MSCs are known to inhibit the growth of tumors of both hematopoietic and non-hematopoietic origin in vitro. In our study, WJ-MSC treatment strongly inhibited the viability of HL-60 and K562 and induced apoptosis. Our results also provided new insights into the inhibition of tumor growth by WJ-MSCs in vitro. In the future, WJ-MSCs could be used to inhibit cancer cells in clinical applications.

The in vitro treatment of mesenchymal stem cells for colorectal cancer cells.

Colorectal cancer is the most common tumor of the gastrointestinal system. The conventional treatment options for colorectal cancer are troublesome for both patients and clinicians. Recently, mesenchymal stem cells (MSCs) have been the novel focus for cell therapy due to their migration to tumor sites. In this study, the apoptotic effect of MSCs on colorectal cancer cell lines has been aimed. HCT-116 and HT-29 were selected as the colorectal cancer cell lines. Human umbilical cord blood and Wharton's jelly were used as mesenchymal stem cell sources. To discriminate against the apoptotic effect of MSC on cancer, we also used peripheral blood mononuclear cells (PBMC) as a healthy control group. Cord blood-MSC and PBMC were obtained by ficoll-paque density gradient, and Wharton's jelly-MSC by explant method. Transwell co-culture systems were used as cancer cells or PBMC/MSCs at ratios of 1/5 and 1/10, with incubation times of 24 h and 72 h. The Annexin V/PI-FITC-based apoptosis assay was performed by flow cytometry. Caspase-3 and HTRA2/Omi proteins were measured by ELISA. For both ratios in both cancer cells, it was found that the apoptotic effect of Wharton's jelly-MSC was significantly higher in 72-h incubations (p < 0.006), whereas the effect of cord blood mesenchymal stem cell in 24-h incubations were higher (p < 0.007). In this study, we showed that human cord blood and tissue-derived MSCs treatment led to colorectal cancers to apoptosis. We anticipate that further in vivo studies may shed light on the apoptotic effect of MSC.

Increasing Apoptotic Effect of Cord Blood and Wharton's Jelly-derived Mesenchymal Stem Cells on HT-29.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer worldwide. Recently, mesenchymal stem cells (MSCs) have been considered a suitable cell therapy option for cancer due to their high migration rate to the tumor site. OBJECTIVES: The study aimed to compare the effects of human umbilical cord blood derived-MSC (UCMSC) and human Wharton's Jelly derived-MSC (WJ-MSC) on the HT-29 cell line. METHODS: UC-MSC was obtained by Ficoll-Paque density gradient and WJ-MSC by explant method. The characterizations of MSCs and apoptosis assays were performed by flow cytometry, and caspase-3 protein levels were measured by ELISA. RESULTS: After 72 hours of HT-29 cancer cells incubation, it was indicated that WJ-MSC was more effective at 1:5 and 1:10 ratios. Similar results were found for caspase-3 by ELISA. Moreover, WJ-MSC (1:5, p < 0.006; 1:10, p < 0.007) was found to be more effective at both doses compared to UC-MSC. CONCLUSION: In this study, we used two different MSC sources at two different ratios to evaluate the apoptotic effect of MSC in vitro on HT-29 CRC cells. As a result, WJ-MSC indicated a more apoptotic effect on HT-29 cells compared to CB-MSC. We anticipated that this preliminary in vitro study would be extended in future in vitro/in vivo studies. Moreover, investigating the behavior of MSC in colorectal tumor microenvironment will be beneficial for the stem cell therapy approach.

Short Tandem Repeat-Polymerase Chain Reaction (STR-PCR) with Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) Method Using for Chimerism Analysis.

BACKGROUND: Recently molecular chimerism analysis after allogeneic hematopoietic stem cell transplantation (AHSCT) has become more important. The use of quantitative chimerism methods aims to assess the kinetics of engraftment to determine graft rejection and failure or relapse of the underlying disease after AHSCT. An accurate and sensitive determination of chimerism status is mandatory after AHSCT. This study aimed to compare two chimerism methods: Multiplex Short Tandem Repeat-Polymerase Chain Reaction (STR-PCR) and quantitative Real Time-PCR (qRT-PCR). METHODS: Thirty-nine blood samples at +28 day were used to extract DNA. Most patients had been diagnosed with acute leukemia (74.3 %) and other hematological diseases. For Multiplex STR-PCR method, PCR products were separated on an ABI 3130 Genetic Analyzer (Applied Biosystem, USA) and for qRT-PCR, an ABI 7500 (Applied Biosystem, USA) Plate System Real Time Analyzer was used to determine the quantification of chimerism per-centage. RESULTS: Of the 39 analyzed samples, 82% concordant chimerism results were detected for both STR-PCR and qRT-PCR methods. Ten mixed chimerisms (MC) were found by qRT-PCR whereas of only 3 MC cases were detected by STR-PCR. In the discordant group of 7 by qRT-PCR, we observed Acute Graft versus Host Disease (aGVHD). Three MC cases that were detected by both STR- and qRT-PCR methods died because of relapse. CONCLUSIONS: The quantitative chimerism method along with multiplex STR-PCR method is important for early detection of MC. qRT-PCR methods can be valuable options in the prevention of graft failure and assisting with fast and early treatment strategies for patients undergoing AHSCT.