The shape of a cell and its movement are critical to many fundamental biological processes. Cancer cells move and invade other tissues to cause metastasis. The morphological changes required for cell movement involve modifying the actin cytoskeleton as well as actin-containing structures that are also responsible for cell spreading and signal sensing.

We study the effectors and regulators of the Rho GTPases that are integral to pathways modulating the actin architecture. In particular, kinases that are activated by the Rho GTPases. The kinases and their substrates are in turn regulated by phosphatases. We are keen to understand how these kinases and phosphatases function to regulate the actin cytoskeleton.

The main areas of our research are (1) signal transduction in cancer biology; (2) functional relationship between actin cytoskeleton regulation and cell cycle control; (3) regulation of the actin cytoskeleton in embryonic stem cells; (4) drug discovery in tropical medicinal plants.

Koh Cheng GeeLEAD PI
Koh Cheng Gee
Associate Chair (Faculty), School of Biological Sciences
Associate Professor, School of Biological Sciences

Phone: (65) 6316 2854
Office: SBS-03N-41
HE Qianqian
Research Fellow

Zhang Songjing
Research Fellow

WOON Jessie Yong Xing
Project Officer

Ph.D. student



I. Cancer Microenvironment and its impact on Cancer Biology.
The tumour microenvironment is complex and can influence the state of tumour proliferation and progression to metastasis. The tumour mass itself is affected by both biochemical and physical cues from its environment. We are interested to investigate the relationship and impact of the tumour microenvironment and cancer biology. The main research topics are listed below.
  1. Cancer microenvironment and mechanosensitive genes.
  2. Tumours in 2D and 3D environment.

II. Functional Relationship between Actin Cytoskeleton Regulation and Cell Cycle Progression.
The actin cytoskeleton is crucial in the maintenance of cell shape and regulation of cellular functions. In this study, we aim (i) to investigate how the actin cytoskeleton modulate cell division events and (ii) to identify the biochemical pathways and molecules involved in the functional integration of actin cytoskeleton and cell cycle.

III. Regulation of Embryonic Stem Cell Pluripotency and Differentiation by Biochemical and Biophysical Cues
In this project, we plan to investigate how the focal adhesions in the ES cells can affect mechanosensing and differentiation of the ES cells.

IV. Drug Discovery in Tropical Medicinal Plants.
Our latest venture is into tropical medicinal plants and herbs. We have isolated active compounds from tropical herbs and are investigating the anti-cell proliferation mechanisms in cancer cells.
  • Kim PR, Koon YL, Lee RTC, Azizan F, Koh DHZ, Chiam KH* and Koh CG*. 2020. Phosphatase POPX2 interferes with cell cycle by interacting with Chk1. Cell Cycle, 19: 405-418. DOI:10.1080/15384101.2020.1711577.
  • Rahmat MB, Zhang S and Koh CG*. 2019. POPX2 is a novel LATS phosphatase that regulates the Hippo pathway. Oncotarget, 10: 1525-1538. DOI:10.18632/oncotarget.26689.
  • Ou S, Tan MH, Weng T, Li HY and Koh CG*. 2018. LIM kinase1 regulates mitotic centrosome integrity via its activity on dynein light intermediate chains. Open Biology, 8: 170202 doi: 10.1098/rsob.170202
  • Weng T and Koh CG*. 2017. POPX2 phosphatase regulates apoptosis through the TAK1-IKK-NFkB pathway. Cell Death & Disease. 8: e3051; doi 10.1038/cddis.2017.443
  • Zhang S, Weng T, Guo T, Cheruba E, Chan H, Sze SK and Koh CG*. 2017. Phosphatase POPX2 exhibits dual regulatory functions in cancer metastasis. Journal of Proteome Research, 16: 698-711
  • Khaw SL, Chua MW, Koh CG*, Lim B and Shyh-Chang N*. 2015. Oocyte factors suppress mitochondrial polynucleotide phosphorylase to remodel the metabolome and enhance reprogramming. Cell Reports, 12:1080-1098. * corresponding authors.
  • Hoon JL, Li HY and Koh CG*. 2014. POPX2 phosphatase regulates cell polarity and centrosome placement. Cell Cycle, 13: 2459-2468.
  • Phang HQ, Hoon JL, Lai SK, Zeng Y, Chiam KH, Li HY and Koh CG*. 2014. POPX2 phosphatase regulates the KIF3 kinesin motor complex. Journal of Cell Science, 127:727-739.
  • Heng YW, Lim HH, Mina T, Utomo P, Zhong S, Lim CT and Koh CG*. 2012. TPPP acts downstream of RhoA-ROCK-LIMK2 to regulate astral microtubule organization and spindle orientation. Journal of Cell Science, 125: 1579-1590.
  • Wong CH, Chan H, Ho CY, Lai SK, Chan KS, Koh CG* & Hoi-Yeung Li*. 2009. Apoptotic histone modification inhibits nuclear transport by regulating RCC1. Nature Cell Biology, 11: 36-45.