The currently used anti-cancer therapies work by killing cancer cells but result in adverse effects and resistance to treatment, which accelerates aging and causes damage to normal somatic cells. On one hand, chicken and zebrafish embryos can reprogram cancer cells towards a non-tumorigenic phenotype; however, they cannot be used in the clinical practice. On the other hand, embryonic stem cells (ESCs) mimic the early embryonic microenvironment and are easily available. We investigated the therapeutic efficacy of the ESC microenvironment (ESCMe) in human uveal melanoma
in vitro
and
in vivo
.
Methods
: Human uveal melanoma C918 cells co-cultured with ESCs were used to measure the levels of mRNA and protein of the phosphoinositide 3-kinase (PI3K) pathway. Cell proliferation, invasiveness, and tumorigenicity of C918 cells were also analyzed. To mimic the tumor microenvironment
in vivo
, we co-cultured C918 cells and normal somatic cells with ESCs in a co-culture system and evaluated the therapeutic potential of ESCMe in both cell types. For an
in vivo
study, a mouse tumor model was used to test the safety and efficacy of the transplanted ESC. Elimination of the transplanted ESCs in mice was carried out by using the ESC-transfected with a thymidine kinase suicidal gene followed by administration of ganciclovir to prevent the formation of teratomas by ESCs.
Results
:
In vitro
studies confirmed that ESCMe inhibits the proliferation, invasiveness, and tumorigenicity of C918 cells, and the PI3K agonist abolished these effects. ESCMe suppressed the various malignant behaviors of uveal melanoma cells but enhanced the proliferation of normal somatic cells both
in vitro
and
in vivo
. Further, we demonstrated that ESCMe suppressed the PI3K pathway in tumor cells but activated in somatic cells.
Conclusions
: The ESCMe can effectively suppress the malignant phenotype of uveal melanoma cells and modulate the tumor-promoting aging environment by preventing the senescence of normal cells through the bidirectional regulation of the PI3K signaling. Our results suggest that ESC transplantation can serve as an effective and safe approach for treating cancer without killing cells.
Obstructive MGD EDE and non-obstructive MGD EDE have significantly different clinical characteristics. Combining average LLT and TMH measurements enhanced their reliability for differentiating these two subtypes and provided guidance for offering more precise treatments for EDE subtypes.
SH eye drops induce a short-term increase in LLT of patients with lipid deficiency. A low concentration of artificial tears have a stronger effect than a high concentration of artificial tears on the increase in LLT. In comparison, SH eye drops induce a transient and slight decrease in LLT of patients without lipid deficiency. A low concentration of artificial tears might be better for patients with lipid deficiency.
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