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Mesenchymal stem cells (MSCs) play an important role as immune modulator through interaction with several immune cells, including macrophages. In this study, the immunomodulatory potency of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) was demonstrated in the in vivo middle cerebral artery occlusion (MCAo)-induced brain injury rat model and in vitro THP-1-derived macrophages model. At 24 h after induction of MCAo, hUC-MSCs was administered via tail vein as a single dose. Remarkably, hUC-MSCs could inhibit M1 polarization and promote M2 polarization of microglia in vivo after 14 days induction of MCAo. Compared with THP-1-derived macrophages which had been stimulated by lipopolysaccharide, the secretion of proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interferon-γ inducible protein (IP-10), were significantly reduced in the presence of hUC-MSCs. Moreover, the secretion of anti-inflammatory cytokine, interleukin-10 (IL-10), was significantly increased after cocultured with hUC-MSCs. Prostaglandins E2 (PGE2), secreted by hUC-MSCs, is one of the crucial immunomodulatory factors and could be inhibited in the presence of COX2 inhibitor, NS-398. PGE2 inhibition suppressed hUC-MSCs immunomodulatory capability, which was restored after addition of synthetic PGE2, establishing the minimum amount of PGE2 required for immunomodulation. In conclusion, our data suggested that PGE2 is a crucial potency marker involved in the therapeutic activity of hUC-MSCs through macrophages immune response modulation and cytokines regulation. This study provides the model for the development of a surrogate quantitative potency assay of immunomodulation in stem cells production.

The aim of this study is to evaluate the feasibility and usefulness of the human umbilical cord mesenchymal stem cells (hUC-MSCs) and hyaluronan acid (HA) combination to attenuate osteoarthritis progression in the knee while simultaneously providing some insights on the mitigation mechanism. In vitro, the effect of hUC-MSCs with HA treatment on chondrocyte cell viability and the cytokine profile were analyzed. Additionally, the antioxidation capability of hUC-MSCs-CM (conditioned medium) with HA towards H2O2-induced chondrocyte cell damage was evaluated. The HA addition increased the hUC-MSC antioxidation capability and cytokine secretion, such as Dickkopf-related protein 1 (DKK-1) and hepatocyte growth factor (HGF), while no adverse effect on the cell viability was observed. In vivo, the intra-articular injection of hUC-MSCs with HA to a mono-iodoacetate (MIA)-induced knee osteoarthritis (KOA) rat model was performed and investigated. Attenuation of the KOA progression in the MIA-damaged rat model was seen best in hUC-MSCs with a HA combination compared to the vehicle control or each individual element. Combining hUC-MSCs and HA resulted in a synergistic effect, such as increasing the cell therapeutic capability while incurring no observable adverse effects. Therefore, this combinatorial therapy is feasible and has promising potential to ameliorate KOA progression.

Oral cancer is the eighth most common type of cancer among men worldwide, with an age-standardized rate of 6.3 per 100,000, and is the fourth leading cause of cancer-associated mortality among men in Taiwan. Cisplatin and 5-fluorouracil (5-FU) are two of the most frequently utilized chemotherapy drugs for the treatment of oral cancer. Although oral cancer patients initially benefit from chemotherapy with these drugs, they may develop resistance to them, which worsens their prognosis and reduces survival rates. It has been reported that increased levels of epidermal growth factor receptor (EGFR) and multidrug resistance-associated protein 2 (MRP2) induce drug resistance in numerous types of human cancer. Therefore, the present study employed lentivirus vector-mediated RNA interference (RNAi) in order to target the genes encoding EGFR and MRP2 in the oral squamous cell carcinoma cell line OC2. It was observed that RNAi-mediated downregulation of EGFR or MRP2 increased the sensitivity to 5-FU and cisplatin in OC2 cells. Downregulation of EGFR resulted in significant suppression of OC2 tumor growth following 5-FU administration. However, simultaneous downregulation of the two genes did not further suppress the tumor growth, indicating that MRP2 does not have a significant role in the chemosensitivity of EGFR-downregulated cells to 5-FU. In contrast, downregulation of MRP2 was demonstrated to significantly enhance the therapeutic effects of cisplatin in EGFR-downregulated OC2 tumors. The observation that the expression of MRP2 was positively correlated with the level of cisplatin resistance in cells suggests that RNAi-mediated downregulation of MRP2 may be applicable as a therapeutic approach toward reversing MRP2-dependent cisplatin resistance in oral cancer.

Oral cancer is the eighth most common type of cancer among men worldwide, with an age-standardized rate of 6.3 per 100,000, and is the fourth leading cause of cancer-associated mortality among men in Taiwan. Cisplatin and 5-fluorouracil (5-FU) are two of the most frequently utilized chemotherapy drugs for the treatment of oral cancer. Although oral cancer patients initially benefit from chemotherapy with these drugs, they may develop resistance to them, which worsens their prognosis and reduces survival rates. It has been reported that increased levels of epidermal growth factor receptor (EGFR) and multidrug resistance-associated protein 2 (MRP2) induce drug resistance in numerous types of human cancer. Therefore, the present study employed lentivirus vector-mediated RNA interference (RNAi) in order to target the genes encoding EGFR and MRP2 in the oral squamous cell carcinoma cell line OC2. It was observed that RNAi-mediated downregulation of EGFR or MRP2 increased the sensitivity to 5-FU and cisplatin in OC2 cells. Downregulation of EGFR resulted in significant suppression of OC2 tumor growth following 5-FU administration. However, simultaneous downregulation of the two genes did not further suppress the tumor growth, indicating that MRP2 does not have a significant role in the chemosensitivity of EGFR-downregulated cells to 5-FU. In contrast, downregulation of MRP2 was demonstrated to significantly enhance the therapeutic effects of cisplatin in EGFR-downregulated OC2 tumors. The observation that the expression of MRP2 was positively correlated with the level of cisplatin resistance in cells suggests that RNAi-mediated downregulation of MRP2 may be applicable as a therapeutic approach toward reversing MRP2-dependent cisplatin resistance in oral cancer.