Molecular pathological epidemiology (MPE, also molecular pathologic epidemiology) is a
discipline
Discipline refers to rule following behavior, to regulate, order, control and authority. It may also refer to punishment. Discipline is used to create habits, routines, and automatic mechanisms such as blind obedience. It may be inflicted on ot ...
combining
epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population.
It is a cornerstone of public health, and shapes policy decisions and evide ...
and
pathology
Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in ...
. It is defined as "epidemiology of
molecular pathology and
heterogeneity of disease".
Pathology and epidemiology share the same goal of elucidating
etiology
Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek (''aitiología'') "giving a reason for" (, ''aitía'', "cause"); and ('' -logía''). More completely, e ...
of disease, and MPE aims to achieve this goal at molecular, individual and population levels. Typically, MPE utilizes
tissue pathology resources and data within existing epidemiology studies.
Molecular epidemiology broadly encompasses MPE and conventional-type molecular epidemiology with the use of traditional disease designation systems.
Disease process
Data from
The Cancer Genome Atlas projects indicate that disease evolution is an inherently heterogeneous process.
Each patient has a unique disease process (“the unique disease principle”), considering the uniqueness of the
exposome
An environmental factor, ecological factor or eco factor is any factor, abiotic or biotic, that influences living organisms. Abiotic factors include ambient temperature, amount of sunlight, and pH of the water soil in which an organism lives. Bi ...
and its unique influence on molecular pathologic process.
This concept has been adopted in clinical medicine along with
precision medicine
Precision, precise or precisely may refer to:
Science, and technology, and mathematics Mathematics and computing (general)
* Accuracy and precision, measurement deviation from true value and its scatter
* Significant figures, the number of digit ...
and
personalized medicine
Personalized medicine, also referred to as precision medicine, is a medical model that separates people into different groups—with medical decisions, practices, interventions and/or products being tailored to the individual patient based on the ...
.
Methodology
In MPE, investigators dissect interrelationships between exposures (e.g., environmental, dietary, lifestyle and genetic factors); alterations in cellular or extracellular molecules (disease molecular signatures); and disease evolution and progression.
Investigators can analyze
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...
,
methylome,
epigenome,
metabolome
The metabolome refers to the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The smal ...
,
transcriptome
The transcriptome is the set of all RNA transcripts, including coding and non-coding, in an individual or a population of cells. The term can also sometimes be used to refer to all RNAs, or just mRNA, depending on the particular experiment. The ...
,
proteome
The proteome is the entire set of proteins that is, or can be, expressed by a genome, cell, tissue, or organism at a certain time. It is the set of expressed proteins in a given type of cell or organism, at a given time, under defined conditions. ...
,
microbiome
A microbiome () is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps ''et al.'' as "a characteristic microbial community occupying a reasonably we ...
,
immunity and
interactome. A putative risk factor can be linked to specific molecular signatures.
MPE research enables identification of a new
biomarker
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, p ...
for potential clinical utility, using large-scale population-based data (e.g.,
PIK3CA mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, m ...
in
colorectal cancer to select patients for
aspirin
Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat in ...
therapy).
The MPE approach can be used following a
genome-wide association study
In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of genetic variants in different individuals to see if any varian ...
(GWAS), termed "GWAS-MPE approach".
Detailed disease endpoint phenotyping can be conducted by means of molecular pathology or surrogate
histopathology
Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία '' -logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Sp ...
or
immunohistochemistry
Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to a ...
analysis of diseased tissues and cells within GWAS.
As an alternative approach, potential risk variants identified by GWAS can be examined in combination with molecular pathology analysis on diseased tissues.
This GWAS-MPE approach can give not only more precise effect estimates, even larger effects, for specific molecular subtypes of the disease, but also insights into pathogenesis by linking genetic variants to molecular pathologic signatures of disease.
Since
molecular diagnostics
Molecular diagnostics is a collection of techniques used to analyze biological markers in the genome and proteome, and how their cells express their genes as proteins, applying molecular biology to medical testing. In medicine the technique i ...
is becoming routine clinical practice, molecular pathology data can aid epidemiologic research.
History
MPE began as analysis of risk factors (e.g., smoking) and molecular pathological findings (e.g., ''
KRAS'' G12C
oncogene mutations in lung carcinoma).
Studies to examine the relationship between an exposure and molecular pathological signatures of disease (particularly, cancer) became increasingly common throughout the 1990s and early 2000s.
The use of molecular pathology in epidemiology lacked standardized methodologies and guidelines as well as interdisciplinary experts and training programs.
MPE research required a new
conceptual framework and methodologies (
epidemiological method
The science of epidemiology has matured significantly from the times of Hippocrates, Semmelweis and John Snow. The techniques for gathering and analyzing epidemiological data vary depending on the type of disease being monitored but each study wil ...
) because MPE examines heterogeneity in an
outcome
Outcome may refer to:
* Outcome (probability), the result of an experiment in probability theory
* Outcome (game theory), the result of players' decisions in game theory
* ''The Outcome'', a 2005 Spanish film
* An outcome measure (or endpoint) ...
variable.
The term "molecular pathological epidemiology" was used by
Shuji Ogino
is a molecular pathological epidemiologist, pathologist, and epidemiologist. He is currently Professor of Pathology at Harvard Medical School and Brigham and Women's Hospital, and Professor in the Department of Epidemiology at Harvard T.H. Chan ...
and Meir Stampfer in 2010.
Specific principles of MPE developed following 2010. The MPE
paradigm is in widespread use globally,
and has been a subject of international conferences.
The International Molecular Pathological Epidemiology (MPE) Meeting Series, which was established in 2013, has been open to the research community around the world, and five meetings were held through 2021.
See also
References
Further reading
*
*
*
{{Biology-footer
Epidemiology
Pathology