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Biology subjects

Elacqua, J. J.

Publications and source records attributed to Elacqua, J. J..

2 recordsLinked to original sources

Low lamin A levels enhance confined cell migration and metastatic capacity in breast cancer

Aberrations in nuclear size and shape are commonly used to identify cancerous tissue. However, it remains unclear whether the disturbed nuclear structure directly contributes to the cancer pathology or is merely a consequence of other events occurring during tumorigenesis. Here, we show that highly invasive and proliferative breast cancer cells have lower expression of the nuclear envelope proteins lamin A/C, leading to increased nuclear deformability that permits enhanced cell migration through confined environments that mimic interstitial spaces encountered during metastasis. Importantly, increasing lamin A/C expression in highly invasive breast cancer cells altered expression of numerous other proteins implicated in metastatic progression. Further supporting an important role of lamins in breast cancer metastasis, analysis of lamin levels in human breast tumors revealed a significant association between lower lamin A levels and decreased disease-free survival. These findings suggest that downregulation of lamin A/C may influence both biochemical and physical properties of the cell to promote breast cancer metastatic progression.

cancer biology↗

NickSeq for genome-wide strand-specific identification of DNA single-strand break sites with single nucleotide resolution

DNA single-strand breaks (SSBs), or nicks, are the most common form of DNA damage. Nicks occur at rates of tens of thousands per cell per day, and result from many sources including oxidative stress and endogenous enzyme activities. Accumulation of nicks, due to high rates of occurrence or defects in repair enzymes, has been implicated in multiple diseases. However, improved methods for nick analysis are needed to learn how their locations and number affect cells, disease progression, and health outcomes. In addition to natural processes including DNA repair, leading genome-editing technologies rely on nuclease activity, including nick generation, at target sites. There is currently a pressing need for methods to study unintended nicking activity genome-wide to evaluate the impact of emerging genome editing tools on cells and organisms. Here we developed a new method, NickSeq, for efficient strand-specific profiling of nicks in complex DNA samples with single nucleotide resolution and low false-positive rates. NickSeq produces deep sequence datasets enriched for reads near nick sites and establishes a readily detectable mutational signal that allows for determination of the nick site and strand. In this work, we apply NickSeq to profile off-target activity of the Nb.BsmI nicking endonuclease and an engineered spCas9 nickase. NickSeq will be useful in exploring the relevance of spontaneously occurring or repair-induced DNA breaks in human disease, DNA breaks caused by DNA damaging agents including therapeutics, and the activity of engineered nucleases in genome editing and other biotechnological applications.

genomics↗