Related Experiment Video
Updated: Feb 13, 2026

Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy
Published on: December 15, 2011
MutL protein homologue 1(MLH1) in colon adenocarcinomas of the dog: minireview
Abstract:
The mismatch repair gene MLH1 is a gene encoding the mismatch repair protein MutL homolog 1 (MLH1), important for repairing mutations generated during DNA replication. MLH1 absence has been observed in human gastrointestinal tumours as well as tumours of the female reproductive tract. We describe the functions of MLH 1 in cell cycle regulation and DNA mismatch repair. In this sense we discuss foriegn knowledges, in which the canine colon adencarcinoma is less frequently diagnosed in Czech and Slovak regions. We briefly described a molecular mechanism of evolution of MSI+ and MSI- colorectal carcinomas in human, and this was confronted with the current opinion of canine colon adenocarcinomas. We suppose that canine colon adenocarcinomas may occur in higher frequency, but they are underdiagnosed in the clinical veterinary practice. At the end, we describe two cases of dogs diagnosed with colorectal adenocarcinoma. The authors propose the centralized collection of colon adenocarcinoma samples from dogs, in one reference veterinary histopathological laboratory, which would analyse mismatch repair proteins.
Insights
MLH1 gene absence is linked to tumors. Canine colon adenocarcinomas may be underdiagnosed, prompting a call for centralized sample collection and analysis of mismatch repair proteins in dogs.
Area of Science:
- Oncology
- Molecular Biology
- Veterinary Pathology
Background:
- The MLH1 gene encodes MutL homolog 1 (MLH1), crucial for DNA repair and cell cycle regulation.
- MLH1 absence is observed in human gastrointestinal and female reproductive tract tumors.
- Understanding MLH1 function is vital for cancer research.
Observation:
- Canine colon adenocarcinomas are reportedly less frequent in Czech and Slovak regions.
- Human colorectal carcinomas exhibit distinct molecular evolution pathways (MSI+ vs. MSI-).
- This study contrasts human colorectal carcinoma evolution with current understanding of canine counterparts.
Findings:
- Canine colon adenocarcinomas may be underdiagnosed in veterinary clinical practice.
- Two cases of canine colorectal adenocarcinoma are presented.
- A hypothesis suggests canine colon adenocarcinomas might occur more frequently than reported.
Implications:
- Proposes centralized collection of canine colon adenocarcinoma samples for analysis.
- Advocates for a reference veterinary histopathology laboratory to analyze mismatch repair proteins in dogs.
- Aims to improve diagnosis and understanding of canine colorectal cancer through standardized analysis.
Related Concept Videos
The Colonization of Land
SN1 Reaction: Stereochemistry
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
SN1 Reaction: Kinetics
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...
SN1 Reaction: Mechanism
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
Predicting Products: SN1 vs. SN2
With increased substitution on the alkyl halide,...

