Introduction: Resistance towards treatment is one of the challenges in breast cancer therapy. Recent studies show the link between lipoprotein with cancer resistance and progression. Clinical data indicates that oxidized low-density lipoprotein (oxLDL) and very low-density lipoprotein (VLDL) play roles the progression of breast cancer. Therefore, purpose of this study was to determine the roles of lipoproteins on migration of breast cancer cell and compare the effects of oxLDL and VLDL. Methods: Parent MCF-7 cells were purchased from ATCC, while the Tamoxifen-resistant MCF-7 (Tam-R MCF-7) was developed by pulse treatment method. Tam-R cells were treated with gradual increase in tamoxifen concentration for 72 hours in Dulbecco’s Modified Eagle’s medium (DMEM) without phenol red. Cell vi- ability test was done to measure the fold changes of Tam-R MCF-7 cells. Migration characteristics was studied using wound healing assay. Cells were treated with 10 μg/mL of oxLDL and VLDL up to 72 hours. Results: From the cell viability test, Tam-R MCF-7 cells had 4-fold increase of resistance than parental cells. Tam-R MCF-7 had acquired resistance to Tamoxifen and achieved a clinically relevant level of resistance. Lipoproteins were found to cause morphological changes, where cells exhibited elongation and dendritic-like growth compared to control cells. Both MCF-7 parental cells and Tam-R MCF-7 cells showed higher percentage of wound closure when treated with oxLDL. In contrast, VLDL treatment caused reduction in cell migration compared to oxLDL. Conclusion: Findings suggest that oxLDL may further promote resistant breast cancer cell migration compared to VLDL.
Introduction: Kratom or (Mitragyna speciosa) leaves are consumed as a folk remedy and opioid substitute in the Southeast Asian region. There is still a lack of information about the long-term or toxic-causing effects of kratom use. Methods: A total of thirteen regular kratom users, with long-term (>20 twenty years) kratom use history were recruited for this cross-sectional pilot study. Respondents were required to undergo a blood-test and laboratory anaysis was conducted to determine the mitragynine content in an acquired street sample of kratom. Results: The regular, long- term consumption of brewed kratom decoction did not cause any significant alterations in haematological, kidney, liver, thyroid, inflammatory and gastrointestinal analytes in a cohort of kratom users who had no history of substance misuse. However, those who had a higher intake (>3 glasses per day) of kratom exhibited higher lipid values (except for HDL-cholesterol), and a moderate elevation of homocysteine level. Conclusion: Long-term (>20 years with a daily intake of 87.54mg of mitragynine) kratom consumption was not associated with altered biochemical levels, although prolonged and heavy use (>3 glasses daily) may result in cardiovascular risks. The latter finding, however, requires further investigation.