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IR-783, a near-infrared heptamethine cyanine dye, has been reported to possess cancer targeting and anticancer effects; However, the molecular mechanism by which IR-783 exhibits anti-breast cancer activity is unclear. In the present study, the inhibitory effects of IR-783 on the proliferation and migration of breast cancer cells were investigated. Our results revealed that IR-783 inhibited MDA-MB-231 and MCF-7 cell proliferation in a dose- and time-dependent manner by inducing cell cycle arrest at the G0/G1 phase. In addition, a Transwell assay demonstrated that IR-783 treatment suppressed the migratory ability of MDA-MB-231 and MCF-7 cells. Furthermore, IR-783 treatment decreased the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 in MDA-MB-231 cells. Furthermore, IR-783 induced MDA-MB-231 and MCF-7 cell mitochondrial fission, and also decreased the levels of ATP. This was accompanied with a decrease in polymerized filamentous actin, which is the fundamental component of filopodia at the cell surface. Collectively, the results of the present study demonstrated that IR-783 inhibited the proliferation and migration of MDA-MB-231 and MCF-7 cells by inducing mitochondrial fission and subsequently decreasing ATP levels, resulting in cell cycle arrest and filopodia formation suppression. These findings suggest that IR-783 may be developed into an effective novel drug for treating breast cancer.

Bacterial colonies growing on solid surfaces can exhibit robust expansion kinetics, with constant radial growth and saturating vertical expansion, suggesting a common developmental program. Here, we study this process for Escherichia coli cells using a combination of modeling and experiments. We show that linear radial colony expansion is set by the verticalization of interior cells due to mechanical constraints rather than radial nutrient gradients as commonly assumed. In contrast, vertical expansion slows down from an initial linear regime even while radial expansion continues linearly. This vertical slowdown is due to limitation of cell growth caused by vertical nutrient gradients, exacerbated by concurrent oxygen depletion. Starvation in the colony interior results in a distinct death zone which sets in as vertical expansion slows down, with the death zone increasing in size along with the expanding colony. Thus, our study reveals complex heterogeneity within simple monoclonal bacterial colonies, especially along the vertical dimension. The intricate dynamics of such emergent behavior can be understood quantitatively from an interplay of mechanical constraints and nutrient gradients arising from obligatory metabolic processes. Bacterial colonies growing on solid surfaces can exhibit robust expansion kinetics, with constant radial growth and saturating vertical expansion. Here, the authors use modeling and experiments to show that colony growth dynamics are driven by an interplay of mechanical constraints and nutrient gradients arising from obligatory metabolic processes.

The role of vitamin D in the prevention of colorectal cancer (CRC) has been the focus of research, but the results of relevant studies are not entirely consistent. While most studies indicate that vitamin D has a protective effect against CRC, there are also research reports stating that at high serum levels, there is no significant association between vitamin D and CRC, or even an increased risk. Additionally, there are still differences in the recommended serum 25-hydroxyvitamin D [25(OH)D] concentrations among various guidelines or committees. This study examined the association between serum 25-hydroxyvitamin D concentrations and the risk of CRC in US adults. This study included 43,678 adult participants from the National Health and Nutrition Examination Survey (NHANES) 2001-2018, and logistic regression modelling was used to examine the association between serum 25(OH)D concentrations and the risk of CRC. We grouped participants according to the classification criteria of the various guidelines available for vitamin D, and controlled for confounding using a multi-model strategy, adjusting for key covariates such as gender, age, race, education level, marital status, family income to poverty ratio (PIR), body mass index (BMI), smoking habits, drinking habits, diabetes, hypertension, dyslipidemia, calcium intake, and total folate intake. We also performed trend tests to evaluate the linear relationship between serum 25(OH)D concentrations and CRC risk, used restricted cubic spline (RCS) plots to assess the dose-response relationship, and conducted further subgroup analyses with interaction tests to examine potential variations in the association across different population groups. We focused on the association between serum 25(OH)D concentration ≤ 75 nmol/L and CRC, again using multivariable logistic regression with a multi-model strategy and RCS plots. A total of 43,382 participants without CRC and 296 participants with CRC were included in this study. In the fully adjusted model, participants with serum 25(OH)D < 50 nmol/L had more than twice the risk of developing CRC compared to those with levels of 50-< 75 nmol/L (<30 nmol/L: Odds Ratio [OR] = 2.038, 95% Confidence Interval [CI]: 1.011-4.109; 30- < 50 nmol/L: OR = 2.090, 95% CI: 1.361-3.211). The negative correlation between serum 25(OH)D concentration and the risk of CRC was significant when serum 25(OH)D concentration was ≤ 75 nmol/L (P < 0.001). Each 1 nmol/L increase in serum 25(OH)D concentration was associated with an approximately 2.3% reduction in the risk of CRC (95% CI: 0.964-0.990). Our findings indicate a strong inverse association between serum 25(OH)D concentrations and the risk of CRC, particularly when levels are ≤75 nmol/L. Maintaining serum 25(OH)D above 75 nmol/L is associated with a lower CRC risk and may serve as a cost-effective preventive strategy. Public health measures, including routine vitamin D screening in high-risk populations and targeted supplementation, could further support CRC prevention efforts.

Bacterial colony growth on hard agar is commonplace in microbiology; yet, what occurs inside a growing colony is complex even in the simplest cases. Robust colony expansion kinetics featuring a linear radial growth and a saturating vertical growth indicates a common developmental program which is elucidated here for Escherichia coli cells using a combination of modeling and experiments. Radial colony expansion is found to be limited by mechanical factors rather than nutrients as commonly assumed. In contrast, vertical expansion is limited by glucose depletion inside the colony, an effect compounded by reduced growth yield due to anaerobiosis. Carbon starvation in the colony interior results in substantial cell death within 1-2 days, with a distinct death zone that expands with the growing colony. Overall, the development of simple colonies lacking EPS production and differentiation is dictated by an interplay of mechanical constraints and emergent nutrient gradients arising from obligatory metabolic processes.