Tag Archives: dna

Malignant cells adopt different pathway for genome duplication

For one of our cells to give birth to two daughter cells, it must first replicate its DNA which consists of around 6.4 billion pairs of nucleotides. The double-stranded DNA opens up like a zipper, producing a ‘replication fork’ upon which a group of enzymes move about. Present in different regions in the DNA, the forks move with the progression of the replication. Cell proliferation is controlled in particular by specific genes known as proto-oncogenes…

Fundamental differences found between human cancers, genetically engineered mouse models

These genetically engineered mouse models (which usually either overexpress a cancer-causing gene — or "oncogene" — or carry a deletion for a "tumor suppressor" gene) have been extensively used to understand human cancer biology in studies of drug resistance, early detection, metastasis, and cancer prevention, as well as for the preclinical development of novel targeted therapeutics. Cancer is a multistep process that involves a complex interplay between genetic and epigenetic alterations. Epigenetic modifications mediate changes in gene expression without altering the DNA sequence. …

Decreased diversity of bacteria microbiome in gut associated colorectal cancer

Previous studies suggest a role for the gut microbiota in colorectal cancer (CRC), but comprehensive epidemiological studies comparing samples from case and control subjects that also consider potential confounders and adjust for multiple comparisons inherently involved in microbiome analysis have not been reported. Jiyoung Ahn, Ph.D., from Department of Population Health at New York University School of Medicine in New York, NY, and colleagues compared samples and data from participants enrolled in a case-control study…

Carbon monoxide may help shrink tumors, amplify effectiveness of chemotherapy

The surprising new findings, described in the December issue of the journal Cancer Research, show that in cell culture and animal models carbon monoxide (CO) can both prevent tumor growth in prostate and lung cancers and can amplify the effectiveness of chemotherapy 1,000-fold — while sparing noncancerous tissue from chemo’s sometimes debilitating side effects. "We found that in small, carefully controlled doses, CO not only mimicked the effects of chemotherapy agents by blocking proliferation of cancer cells, but also amplified the toxic effects of the chemotherapy drugs doxorubicin and camptothecin to accelerate cancer cell death," says senior author Leo Otterbein, PhD, an investigator in the Transplant Institute in BIDMC’s Department of Surgery and Associate Professor of Surgery at Harvard Medical School. "Importantly and rather unique is that CO also helped to protect normal tissue from chemotherapy, which is an unfortunate side effect of the treatments." The new discovery appears to hinge on CO’s ability to switch the metabolic state of cancer cells so that tumors essentially work themselves to death…

Leukemia cells exploit ‘enhancer’ DNA elements to cause lethal disease

The research, appearing today in Genes & Development and led by CSHL Assistant Professor Chris Vakoc, centers on the way a cancer-promoting gene is controlled. When this oncogene, called Myc, is robustly expressed, it instructs cells to manufacture proteins that contribute to the uncontrolled growth that is cancer’s hallmark. The Myc oncogene is also implicated in many other cancer types, adding to the significance of the new finding…

Hallmark for development of testicular tumors found in genes

In human spermatozoa, these tiny RNAs are epigenetically regulated (by changes in the genome that do not alter the DNA sequence, such as DNA methylation) and play a critical role in male germline development. Importantly, these RNAs have also been detected in human cancer cells. In a work published in the January 2014 issue of Epigenetics, which is entirely devoted to "Non-coding RNAs in Epigenetic Regulation," the researchers asked if in their natural functional context (the normal human testis) these small RNAs undergo aberrant epigenetic regulation, compromising their function and contributing to the transformation of cells into testicular tumor cells. …

New technique improves accuracy, ease of cancer diagnosis

The technique, which uses a deformability cytometer to analyze individual cells, could reduce the need for more cumbersome diagnostic procedures and the associated costs, while improving accuracy over current methods. The initial clinical study, which analyzed pleural fluid samples from more than 100 patients, was published in the current issue of peer-reviewed journal Science Translational Medicine. Pleural fluid, a natural lubricant of the lungs as they expand and contract during breathing, is normally present in spaces surrounding the lungs. …