If we unraveled the DNA of the 46 chromosomes of a single human cell, it would barely measure 2 meters. If we did the same with the rest of the body, if we aligned the 3 billion base pairs of its 5 trillion cells, we could travel the distance from the Earth to the Sun more than 100 times. It seems unreachable. However, that is the unit of knowledge of the large sequencing projects achieved in 2023. From the generation of the human pangenome to cell-by-cell maps of the brain and kidneys, scientists this year have completed several omics collaborative projects stored in large international databases. Now, what’s the plan?
Launching a company based on knowledge that “the fundamental principle that most people hold to be true is off by a trillion” is a rare opportunity, said Jake Rubens, co-founder and president of Quotient Therapeutics Inc., a company that emerged from stealth this week, backed by two years of platform development and a $50 million investment from Flagship Pioneering.
The human genome, the sequence that represents the DNA of our species, was built with a single individual as a model. This all-in-one standard didn’t include the gene variations that make us different or explain why some people develop certain diseases. Four simultaneous studies from the Human Pangenome Reference Consortium have published a sequence based on 47 individuals, beginning to capture the genetic diversity that defines humans.
A method for parallel sequencing of single-cell extrachromosomal circular DNA (ecDNA) and full-length mRNA transcriptomes has enabled new insights into the roles of ecDNA in cancer progression, researchers from Charité hospital and the Max Delbrück Center for Molecular Medicine reported in Nature Genetics on May 8, 2023. Circular DNAs are present in at least a third of cancer cells, and their presence correlates with poor prognosis in many cases. They can carry driver genes that have separated themselves from their chromosome of origin, and some research suggests that they serve as “reserve copies” of driver genes. Boundless Bio Inc. is in phase I trials targeting ecDNAs.
Cells that break away from a tumor and colonize other regions of the body express genes that are different from those of the cancer from which they originate. Now, a Baylor College of Medicine study has found that metastases can be classified into four cancer subtypes regardless of the primary cancer. This finding describes which genes are active in each one, making it possible to establish the most appropriate treatments for each patient according to the subtype of metastasis they have developed.
A genome-wide association study (GWAS) from The University of Queensland has linked blood cell traits (BCTs) and neurological and psychiatric disorders (NPDs), providing a tool to improve patient treatments or repurposing different drugs. The researchers also found a cause-effect relationship between Parkinson's and platelet distribution width. In their study, published Jan. 25, 2023, in Cell Genomics, the scientists observed the genetic overlap between common NPDs and 29 BCTs, including functional genes, regulatory elements and new genetic correlations linked to hematological data and for these diseases.
Los Angeles is one of the most diverse cities in the U.S. This diversity is evident at University of California, Los Angeles (UCLA), a university that attracts students (37,000) and workers (22,090) from 118 countries. It is enough to go for a walk on campus or its surroundings to believe that one is at a United Nations convention. Researchers at the UCLA ATLAS Community Health Initiative has been capturing that diversity in a genomic biobank whose data will help to understand, anonymously, the genetic basis of certain diseases. With them, scientists will be able to design the best treatments for these patients.
X-chromosome inactivation (XCI) is not unique to female cells and may confer some survival advantage to male cancer cells, according to scientists at the Dana-Farber Cancer Institute at Harvard. The noncoding RNA XIST (acronym for X-inactive specific transcript), which in female mammals (of genotype XX) inactivates one of the X chromosomes, preventing the overexpression of the genes of the repeated chromosome from early stages of embryonic development, also acts somatically in some male cancers, compensating for the loss of the entire chromosome.
“We found that a small percentage of male cancers are expressing XIST, which normally is expressed in female cancers. And the percentage of male cancers that express XIST is variable depending on the cancer type,” Srinivas Viswanathan, researcher in the Department of Medical Oncology at the Dana-Farber Cancer Institute at Harvard and assistant professor of Medicine at Harvard Medical School, told BioWorld.
In the largest study to date for Crohn's disease, researchers from the Wellcome Sanger Institute and the Broad Institute of MIT and Harvard identified rare variants of 10 genes associated with this pathology. The researchers sequenced the exomes of 110,000 people, 30,000 patients with Crohn's and 80,000 without this condition, with the participation of a hundred international scientific institutions.