We previously reported that overexpression of cytochrome P450 family 24 subfamily A member 1 (CYP24A1) increases lung cancer cell proliferation by activating RAS signaling and that CYP24A1 knockdown inhibits tumor growth. However, the mechanism of CYP24A1-mediated cancer cell proliferation remains unclear. Here, we conducted cell synchronization and biochemical experiments in lung adenocarcinoma cells, revealing a link between CYP24A1 and anaphase-promoting complex (APC), a key cell cycle regulator. We demonstrate that CYP24A1 expression is cell cycle–dependent; it was higher in the G2-M phase and diminished upon G1 entry. CYP24A1 has a functional destruction box (D-box) motif that allows binding with two APC adaptors, CDC20-homologue 1 (CDH1) and cell division cycle 20 (CDC20). Unlike other APC substrates, however, CYP24A1 acted as a pseudo-substrate, inhibiting CDH1 activity and promoting mitotic progression. Conversely, overexpression of a CYP24A1 D-box mutant compromised CDH1 binding, allowing CDH1 hyperactivation, thereby hastening degradation of its substrates cyclin B1 and CDC20, and accumulation of the CDC20 substrate p21, prolonging mitotic exit. These activities also occurred with a CYP24A1 isoform 2 lacking the catalytic cysteine (Cys-462), suggesting that CYP24A1's oncogenic potential is independent of its catalytic activity. CYP24A1 degradation reduced clonogenic survival of mutant KRAS-driven lung cancer cells, and calcitriol treatment increased CYP24A1 levels and tumor burden in Lsl-KRASG12D mice. These results disclose a catalytic activity-independent growth-promoting role of CYP24A1 in mutant KRAS-driven lung cancer. This suggests that CYP24A1 could be therapeutically targeted in lung cancers in which its expression is high.

(University of Barcelona) The yellow-legged gull has a high ability to adapt to human activities and benefit from these as a food resource during all year. This is stated in a scientific article published in the journal Ecology and Evolution whose first author is the researcher Francisco Ramírez, from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona.

(Cornell University) To help future scientists make sense of what their telescopes are showing them, Cornell University astronomers have developed a spectral field guide for rocky worlds orbiting white dwarf stars.

(University of Arkansas) Giant elliptical galaxies are not as likely as disk-shaped galaxies, such as our own Milky Way, to be cradles of technological civilizations, according to a recent paper by a University of Arkansas astrophysicist.

(Arizona State University) An interdisciplinary team of researchers, led by Arizona State University, has provided a framework called a 'detectability index' to help prioritize exoplanets to study and provide scientists with a tool to select the best targets for observation and maximize the chances of detecting life.

(Universitat Autonoma de Barcelona) More than 500 researchers from all around the world will gather virtually tomorrow Wednesday May 6 at the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) to discuss and propose how society should adopt more sustainable and low-carbon forms of lifestyle that contribute to mitigating climate change.

(Marine Biological Laboratory) Microbial life is bubbling up to the ocean floor along with fluids from deeply buried petroleum reservoirs, reports a team of scientists from the University of Calgary and the Marine Biological Laboratory, Woods Hole.

As part of the College's move to remote learning, 143 first-year students are taking a series of virtual field courses to investigate biodiversity.

(University of Sydney) Data centres and digital information processors are reaching their capacity limits and producing heat. Foundational work here on optical-acoustic microchips opens door to low-heat, low-energy, fast internet.

(University of Huddersfield) A team of researchers received funding of almost £130,000 to work with a group of women in Zambia and create songs that warn against the dangers of the coronavirus -- and now New York wants to hear them.

Russell E. Glasgow
Jan 1, 2001; 14:
Articles

The SBDC offers resources and guidance to Harlem’s small businesses amidst the COVID-19 crisis.