SummaryDiagnostic trends in medicine are being directed toward cellular and molecular processes, where treatment regimens are more amenable for cure. Optical imaging is capable of performing cellular and molecular imaging using the short wavelengths and spectroscopic properties of light. Diffuse optical tomography is an optical imaging technique that has been pursued as an alternative to X-ray mammography. While this technique permits noninvasive optical imaging of the whole breast, to date it is incapable of resolving features at the cellular level. Optical coherence tomography (OCT) is an emerging high-resolution biomedical imaging technology that for larger and undifferentiated cells can perform cellular-level imaging at the expense of imaging depth. OCT performs optical ranging in tissue and is analogous to ultrasound except reflections of near-infrared light are detected rather than sound. In this paper, an overview of the OCT technology is provided, followed by images demonstrating the feasibility of using OCT to image cellular features indicative of breast cancer. OCT images of a well-established carcinogen-induced rat mammary tumor model were acquired. Images from this common experimental model show strong correlation with corresponding histopathology. These results illustrate the potential of OCT for a wide range of basic research studies and for intra-operative image-guidance to identify foci of tumor cells within surgical margins during the surgical treatment of breast cancer.

Fruit extracts of four Vaccinium species (lowbush blueberry, bilberry, cranberry, and lingonberry) were screened for anticarcinogenic compounds by a combination of fractionation and in vitro testing of their ability to induce the Phase II xenobiotic detoxification enzyme quinone reductase (QR) and to inhibit the induction of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, by the tumor promoter phorbol 12-myristate 13-acetate (TPA). The crude extracts, anthocyanin and proanthocyanidin fractions were not highly active in QR induction whereas the ethyl acetate extracts were active QR inducers. The concentrations required to double QR activity (designated CDqr) for the ethyl acetate extracts of lowbush blueberry, cranberry, lingonberry, and bilberry were 4.2, 3.7, 1.3, and 1.0 microgram tannic acid equivalents (TAE), respectively, Further fractionation of the bilberry ethyl acetate extract revealed that the majority of inducer potency was contained in a hexane/chloroform subfraction (CDqr = 0.07 microgram TAE). In contrast to their effects on QR, crude extracts of lowbush blueberry, cranberry, and lingonberry were active inhibitors of ODC activity. The concentrations of these crude extracts needed to inhibit ODC activity by 50% (designated IC50) were 8.0, 7.0, and 9.0 micrograms TAE, respectively. The greatest activity in these extracts appeared to be contained in the polymeric proanthocyanidin fractions of the lowbush blueberry, cranberry, and lingonberry fruits (IC50 = 3.0, 6.0, and 5.0 micrograms TAE, respectively). The anthocyanidin and ethyl acetate extracts of the four Vaccinium species were either inactive or relatively weak inhibitors of ODC activity. Thus, components of the hexane/chloroform fraction of bilberry and of the proanthocyanidin fraction of lowbush blueberry, cranberry, and lingonberry exhibit potential anticarcinogenic activity as evaluated by in vitro screening tests.

Triterpenoid B-group soyasaponins have been found to induce macroautophagy in human colon cancer cells at concentrations obtainable through consumption of legume foodstuffs. In the present studies the mechanism(s) for this autophagy-inducing action of soyasaponins was evaluated by measuring changes in signal transduction pathways associated with autophagy. Specifically, inhibition of the Akt signaling pathway and enhanced activity of ERK1/2 have previously been implicated in controlling induction of macroautophagy in mammalian cancer cells. Here we show that these pathways are also involved in B-group soyasaponin-induced macroautophagy, as changes in enzyme activities preceded significant increases in autophagic activity. The autophagic capacity of HCT-15 cells was significantly increased by 6 h post-saponin exposure, which led us to measure alterations in signaling events that preceded this time point. We determined that exposure to B-group soyasaponins suppressed Akt activity maximally by 50%, which was associated with a reduction in the activating phosphorylation of the Akt-serine473 residue. In addition, ERK1/2 activity was significantly increased by 60%, and was determined to be necessary for B-group soyasaponin-induced autophagy. The raf-1 kinase has been identified as a potential point of cross-talk between the Akt and ERK1/2 signaling cascades. Following B-group soyasaponin treatment activity of raf-1 was significantly increased by a maximal 200%, suggesting that this enzyme in part modulates the enhanced ERK1/2 activity. These results provide new insights into the signaling events that control induction of autophagy by B-group soyasaponins in human colon cancer cells and suggest that soyasaponins warrant further study as potential colon cancer chemopreventive agents.

Sulforaphane (SUL), an isothiocyanate found in broccoli and other cruciferous vegetables, has been shown to induce phase II detoxification enzymes, inhibit chemically induced mammary tumors in rats, and more recently to induce cell cycle arrest and apoptosis in cancer cells of the colon. Here, we provide evidence that SUL also acts as a breast cancer anti-proliferative agent. The BALB/c mouse mammary carcinoma cell line F3II was treated with SUL at concentrations up to 15 microM and examined for markers of cell cycle arrest and apoptosis. Treatment of asynchronous F3II cells with 15 microM SUL resulted in G2/M cell cycle arrest, elevated p34cdc2 (cdc2) kinase activity, Bcl-2 down-regulation, evidence of caspase activation, and aggregation of condensed nuclear chromatin. Subsequent exposure of synchronized cells to 15 microM SUL resulted in elevated numbers of prophase/prometaphase mitotic figures, indicating cell cycle progression beyond G2 and arrest early within mitosis. Moreover, cells treated with 15 microM SUL displayed aberrant mitotic spindles, and higher doses of SUL inhibited tubulin polymerization in vitro. In addition, BALB/c mice injected s.c. with F3II cells and subsequently injected daily i.v. with SUL (15 nmol/day for 13 days) developed significantly smaller tumors (approximately 60% less in mass) than vehicle-treated controls. Western blot analysis of tumor proteins demonstrated significantly (P<0.05) reduced PCNA and elevated PARP fragmentation in samples from animals dosed with SUL. Taken together, these results indicate that SUL has mammary cancer suppressive actions both in cell culture and in the whole animal. Inhibition of mammary carcinogenesis appears in part to involve perturbation of mitotic microtubules and early M-phase block associated with cdc2 kinase activation, indicating that cells arrest prior to metaphase exit.