Human tumor cell proliferation evaluated using manganese-enhanced MRI.

Area of Science:

• Biomedical Imaging
• Oncology
• Cell Biology

Background:

• Tumor cell proliferation is often dependent on calcium ion (Ca2+) influx.
• Developing non-invasive methods to assess tumor proliferation in vivo is crucial.
• Manganese-enhanced MRI (MEMRI) uses Mn(2+) as a calcium surrogate to visualize cellular uptake.

Purpose of the Study:

• To test if tumor cell uptake of Mn(2+) (measured by MEMRI) correlates with proliferation rates in vitro.
• To establish a foundation for a non-invasive in vivo test of tumor proliferation.

Main Methods:

• Three human tumor cell lines (C918, OCM-1 uveal melanomas, PC-3 prostate carcinoma) were cultured in vitro.
• Cells were exposed to manganese chloride (MnCl2), followed by MEMRI R(1) value determination.
• Cell cycle distribution was analyzed using propidium iodide staining and flow cytometry.

Main Results:

• All cell lines showed increased R(1) values after Mn(2+) exposure.
• C918 and PC-3 cells exhibited a significant positive correlation between MEMRI R(1) values and proliferation rate (p≤0.005).
• OCM-1 cells did not show a significant correlation; modeling suggested cell cycle distribution influenced PC-3 R(1) values.

Conclusions:

• The study demonstrates a tumor-cell-dependent link between proliferation and calcium influx.
• MEMRI is a valuable tool for investigating calcium influx in tumor cells.
• Results suggest MEMRI's potential for evaluating tumor proliferation parameters in vivo for certain cancer types.