Related Experiment Video

Updated: Jun 29, 2026

Polymalic Acid-based Nano Biopolymers for Targeting of Multiple Tumor Markers: An Opportunity for Personalized Medicine?
14:20

Polymalic Acid-based Nano Biopolymers for Targeting of Multiple Tumor Markers: An Opportunity for Personalized Medicine?

Published on: June 13, 2014

Upregulated HSP27 in human breast cancer cells reduces Herceptin susceptibility by increasing Her2 protein stability

Se Hun Kang1, Keon Wook Kang, Kyung-Hee Kim

  • 1Research Institute and Hospital, National Cancer Center, Republic of Korea. neology7@ncc.re.kr

BMC Cancer
|October 7, 2008
PubMed
Abstract

Insights

Heat-shock protein 27 (HSP27) upregulation in breast cancer cells confers Herceptin resistance. Suppressing HSP27 increases cell susceptibility to Herceptin by promoting Her2 degradation.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Metastatic breast cancer with Her2 overexpression requires understanding Herceptin resistance mechanisms.
  • Identifying molecular drivers of Herceptin resistance is crucial for effective treatment strategies.

Purpose of the Study:

  • To investigate the molecular mechanisms underlying Herceptin resistance in breast cancer.
  • To explore the role of heat-shock protein 27 (HSP27) in Herceptin resistance.

Main Methods:

  • Comparative proteome analysis of Herceptin-sensitive (SK-BR-3) and Herceptin-resistant (SK-BR-3 HR) human breast cancer cell lines.
  • siRNA-mediated suppression of HSP27 and co-immunoprecipitation assays to study protein interactions.

Main Results:

  • Heat-shock protein 27 (HSP27) expression was significantly upregulated in Herceptin-resistant SK-BR-3 HR cells.
  • HSP27 suppression via siRNA increased SK-BR-3 HR cell sensitivity to Herceptin.
  • HSP27 was found to bind to Her2, and this complex formation appeared to obstruct Herceptin-induced Her2 downregulation, thereby stabilizing Her2 protein.

Conclusions:

  • Upregulated HSP27 contributes to Herceptin resistance in breast cancer by enhancing Her2 protein stability.
  • Targeting HSP27 may represent a therapeutic strategy to overcome Herceptin resistance in Her2-overexpressing breast cancer.

More Related Videos

Validated Immunochemical Assay for Comprehensive Determination of the Human Epidermal Growth Factor Receptor 2 Released from and Bound to Cells08:28

Validated Immunochemical Assay for Comprehensive Determination of the Human Epidermal Growth Factor Receptor 2 Released from and Bound to Cells

Published on: May 9, 2025

Related Concept Videos

Targeted Cancer Therapies02:57

Targeted Cancer Therapies

The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
There are several types of targeted therapies against specific...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...