Related Experiment Video

Updated: May 23, 2026

Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models
09:58

Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models

Published on: December 9, 2016

Expression of a splicing variant of the CADM1 specific to small cell lung cancer

Shinji Kikuchi1, Miwako Iwai, Mika Sakurai-Yageta

  • 1Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan.

Cancer Science
|March 21, 2012
PubMed

Insights

Cell adhesion molecule 1 (CADM1) has dual roles in cancer. In small cell lung cancer (SCLC), CADM1 expression enhances tumor growth and invasiveness, suggesting it could be a specific SCLC marker.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cell Biology

Background:

  • Cell adhesion molecule 1 (CADM1) is an immunoglobulin superfamily member with known tumor suppressor roles.
  • CADM1 exhibits dual functions in oncogenesis, acting as a tumor suppressor in some cancers and promoting invasion in adult T-cell leukemia (ATL).

Purpose of the Study:

  • To investigate the specific roles of CADM1 in small cell lung cancer (SCLC).
  • To determine if CADM1 expression correlates with SCLC phenotypes and to identify potential CADM1 isoforms in SCLC.

Main Methods:

  • Immunohistochemistry to detect CADM1 protein in primary SCLC tumors.
  • Western blotting and RT-PCR to analyze CADM1 expression in SCLC cell lines with different growth characteristics.
  • Transfection and shRNA-mediated suppression to assess the functional impact of CADM1 variants on SCLC cell behavior and tumorigenicity.
  • Analysis of CADM1 splicing variants in SCLC.

Main Results:

  • CADM1 protein was expressed in 29% of primary SCLC tumors.
  • CADM1 expression was significantly higher in SCLC cells with anchorage-independent growth (suspension cultures) compared to attached cells.
  • A unique CADM1 splicing variant (variant 8/9) was identified in SCLC, also found in the testis.
  • Both CADM1 variant 8 and variant 8/9 enhanced tumorigenicity in SCLC cells lacking endogenous CADM1.
  • Suppression of CADM1 reduced spheroid-like aggregation in SCLC cells with high CADM1 expression.

Conclusions:

  • CADM1 plays a role in promoting malignant features of SCLC, including anchorage-independent growth and enhanced tumorigenicity.
  • The unique CADM1 variant 8/9 is predominantly found in SCLC.
  • CADM1 may serve as a specific molecular marker for SCLC, similar to its role in ATL.

More Related Videos

Detection of Alternative Splicing During Epithelial-Mesenchymal Transition11:48

Detection of Alternative Splicing During Epithelial-Mesenchymal Transition

Published on: October 9, 2014

Using the E1A Minigene Tool to Study mRNA Splicing Changes10:25

Using the E1A Minigene Tool to Study mRNA Splicing Changes

Published on: April 22, 2021

Related Concept Videos

RNA Splicing01:32

RNA Splicing

Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
Cadherins in Tissue Organization01:19

Cadherins in Tissue Organization

The cadherins are a superfamily of cell adhesion molecules comprising over 180 variants, with specific tissues expressing a particular combination of cadherin types. Cadherins generally exhibit homophilic binding; i.e., cadherins on one cell bind to cadherins of the same or closely related type on another cell. Thus, cells of the same type have a specific affinity to bind to each other and sort themselves into clusters to form tissues.
Cell Sorting During Development
Cell sorting plays an...
Alternative RNA Splicing02:18

Alternative RNA Splicing

Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Induced Pluripotent Stem Cells01:06

Induced Pluripotent Stem Cells

Stem cells are undifferentiated cells that divide and produce different cell types. Ordinarily, cells that have differentiated into a specific cell type are terminally differentiated; however, scientists have found a way to reprogram these mature cells so that they dedifferentiate and return to an unspecialized, proliferative state. These cells are pluripotent like embryonic stem cells—able to produce all cell types—and are called induced pluripotent stem cells (iPSCs).
Somatic cells are...
Cell Specific Gene Expression01:58

Cell Specific Gene Expression

Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
Cell Specific Gene Expression01:58

Cell Specific Gene Expression

Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...