  We developed and applied rapid scanning laser-emission microscopy to detect
abnormal changes in cell nuclei for early diagnosis of cancer and cancer
precursors. Regulation of chromatins is essential for genetic development and
normal cell functions, while abnormal nuclear changes may lead to many
diseases, in particular, cancer. The capability to detect abnormal changes in
apparently normal tissues at a stage earlier than tumor development is critical
for cancer prevention. Here we report using LEM to analyze colonic tissues from
mice at-risk for colon cancer by detecting prepolyp nuclear abnormality. By
imaging the lasing emissions from chromatins, we discovered that, despite the
absence of observable lesions, polyps, or tumors under stereoscope, high-fat
mice exhibited significantly lower lasing thresholds than low-fat mice. The low
lasing threshold is, in fact, very similar to that of adenomas and is caused by
abnormal cell proliferation and chromatin deregulation that can potentially
lead to cancer. Our findings suggest that conventional methods, such as
colonoscopy, may be insufficient to reveal hidden or early tumors under
development. We envision that this work will provide new insights into LEM for
early tumor detection in clinical diagnosis and fundamental biological and
biomedical research of chromatin changes at the biomolecular level of cancer
development.
