Limits...
Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism.

Ghoneum M, Gimzewski J - Int. J. Oncol. (2014)

Bottom Line: We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics.The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP).In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Charles R. Drew University of Medicine and Science, Los Angeles, CA 90059, USA.

ABSTRACT
We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. The aim of this study was to examine the apoptotic effect of PFT on human multidrug-resistant (MDR) myeloid leukemia (HL60/AR) cells in vitro and explore the mechanistic approach underlying its effect. HL60/AR cells were cultured with PFT (0.6-5.0 mg/ml) for 3 days. The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP). PFT induced apoptosis in HL60/AR cells in a dose-dependent manner which was maximal at 67.5% for 5 mg/ml. Induction of apoptosis was associated with activation of caspase 3, decreased expression of Bcl-2 and decreased polarization of MMP. In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies. This hole induction may be responsible for the apoptotic effect on cancer cells. These results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia.

Show MeSH

Related in: MedlinePlus

Determining the depth of PFT-induced hole formation. The red and blue lines indicate the surface contour of an HL60/AR cell treated with PFT. The arrow indicates a large hole detected by the SNL tip and arrowheads indicate smaller holes. This image is representative of many HL60/AR cells during PFT treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3928472&req=5

f8-ijo-44-03-0830: Determining the depth of PFT-induced hole formation. The red and blue lines indicate the surface contour of an HL60/AR cell treated with PFT. The arrow indicates a large hole detected by the SNL tip and arrowheads indicate smaller holes. This image is representative of many HL60/AR cells during PFT treatment.

Mentions: AFM studies were carried out to examine the morphological changes associated with PFT treatment of HL60/AR cells. Results showed a low percentage of the control untreated HL60/AR cells with holes, as well as a small number of holes per cell (Fig. 6A). When the cancer cells were exposed to L. kefiri P-IF (5 mg/ml) for 2 min, we observed an adherence of L. kefiri P-IF to the cancer cells (Fig. 6B). Exposure of cancer cells to L. kefiri P-IF for a longer time (24 h) resulted in 2.6-fold increase in the percentage of cancer cells with holes. Control untreated cells showed 17.5% had single holes and 2% had multiple holes. However, of the L. kefiri P-IF-treated cells, 42% had single holes and 9.5% had multiple holes. Fig. 6C shows multiple holes surrounding the nucleus. Some of the holes are highly enlarged, as can be seen in Fig. 6D. The holes were situated in the cytoplasm and the nucleus. Fig. 6D and E also shows that hole induction was associated with membrane blebbing and a decrease in the nuclear to cytoplasmic ratio. These morphological changes are considered to be signs of cancer cell apoptosis. The holes were further characterized by peak force imaging (Figs. 7 and 8), where the variation in size, shape and depth of the holes was measured. The color intensity indicates hole depth, with lighter areas being shallow or flat and darker colors indicating depth (Fig. 7). The topography of the cell was traced using a cantilever tip. The changes in the vertical movement of the SNL tip were recorded and visualized in graphic form as seen in Fig. 8. A decrease along the y-axis indicates the presence of a hole on the surface of the cell. During PFT treatment, many holes were detected in HL60/AR cells using this method of analysis (Fig. 8).


Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism.

Ghoneum M, Gimzewski J - Int. J. Oncol. (2014)

Determining the depth of PFT-induced hole formation. The red and blue lines indicate the surface contour of an HL60/AR cell treated with PFT. The arrow indicates a large hole detected by the SNL tip and arrowheads indicate smaller holes. This image is representative of many HL60/AR cells during PFT treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3928472&req=5

f8-ijo-44-03-0830: Determining the depth of PFT-induced hole formation. The red and blue lines indicate the surface contour of an HL60/AR cell treated with PFT. The arrow indicates a large hole detected by the SNL tip and arrowheads indicate smaller holes. This image is representative of many HL60/AR cells during PFT treatment.
Mentions: AFM studies were carried out to examine the morphological changes associated with PFT treatment of HL60/AR cells. Results showed a low percentage of the control untreated HL60/AR cells with holes, as well as a small number of holes per cell (Fig. 6A). When the cancer cells were exposed to L. kefiri P-IF (5 mg/ml) for 2 min, we observed an adherence of L. kefiri P-IF to the cancer cells (Fig. 6B). Exposure of cancer cells to L. kefiri P-IF for a longer time (24 h) resulted in 2.6-fold increase in the percentage of cancer cells with holes. Control untreated cells showed 17.5% had single holes and 2% had multiple holes. However, of the L. kefiri P-IF-treated cells, 42% had single holes and 9.5% had multiple holes. Fig. 6C shows multiple holes surrounding the nucleus. Some of the holes are highly enlarged, as can be seen in Fig. 6D. The holes were situated in the cytoplasm and the nucleus. Fig. 6D and E also shows that hole induction was associated with membrane blebbing and a decrease in the nuclear to cytoplasmic ratio. These morphological changes are considered to be signs of cancer cell apoptosis. The holes were further characterized by peak force imaging (Figs. 7 and 8), where the variation in size, shape and depth of the holes was measured. The color intensity indicates hole depth, with lighter areas being shallow or flat and darker colors indicating depth (Fig. 7). The topography of the cell was traced using a cantilever tip. The changes in the vertical movement of the SNL tip were recorded and visualized in graphic form as seen in Fig. 8. A decrease along the y-axis indicates the presence of a hole on the surface of the cell. During PFT treatment, many holes were detected in HL60/AR cells using this method of analysis (Fig. 8).

Bottom Line: We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics.The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP).In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Charles R. Drew University of Medicine and Science, Los Angeles, CA 90059, USA.

ABSTRACT
We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. The aim of this study was to examine the apoptotic effect of PFT on human multidrug-resistant (MDR) myeloid leukemia (HL60/AR) cells in vitro and explore the mechanistic approach underlying its effect. HL60/AR cells were cultured with PFT (0.6-5.0 mg/ml) for 3 days. The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP). PFT induced apoptosis in HL60/AR cells in a dose-dependent manner which was maximal at 67.5% for 5 mg/ml. Induction of apoptosis was associated with activation of caspase 3, decreased expression of Bcl-2 and decreased polarization of MMP. In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies. This hole induction may be responsible for the apoptotic effect on cancer cells. These results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia.

Show MeSH
Related in: MedlinePlus