Developmentally regulated GTP-binding protein 2 levels in prostate cancer cell lines impact docetaxel-induced apoptosis

김성철,이원혁,김송희,Abdumadjidov Alisher Abdulkhayevich,박정우,김영민,문경현,이상훈,박성찬 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.4

Purpose: This study aimed to confirm the association between developmentally regulated GTP-binding protein 2 (DRG2) expression and docetaxel-induced apoptosis and to determine whether prostate cancer responses to docetaxel treatment differ with DRG2 expression. Materials and Methods: PC3, DU145, and LNCaP prostate cancer cell lines were used. The MTT assay was used to determine cell viability. Western blotting analysis was performed using anti-DRG2 antibodies. Cells were transfected with 50 nmol DRG2 siRNA using an siRNA transfection reagent for DRG2 knockdown. The cell cycle was analyzed by using flow cytometry, and apoptosis was detected by using the Annexin V cell death assay. Results: DRG2 expression differed in each prostate cancer cell line. Docetaxel reduced DRG2 expression in a dose-dependent manner. Upon DRG2 knockdown in prostate cancer cells, an increase in the sub-G1 phase was observed without a change in the G1 or G2/M phases. When 4 nM docetaxel was administered to DRG2 knockdown prostate cancer cell lines, an increase in the sub-G1 phase was observed without increasing the G2/M phase, which was similar to that in DU145 cells before DRG2 knockdown. In PC3 and DU145 cell lines, DRG2 knockdown increased docetaxel-induced Annexin V (+) apoptosis by 8.7 and 2.7 times, respectively. Conclusions: In prostate cancer cells, DRG2 regulates G2/M arrest after docetaxel treatment. In prostate cancer cells with DRG2 knockdown, apoptosis increases without G2/M arrest in response to docetaxel treatment. These results show that inhibition of DRG2 expression can be useful to enhance docetaxel-induced apoptosis despite low-dose administration in castration-resistant prostate cancer.

Developmentally regulated GTP-binding protein 2 is required for stabilization of Rac1-positive membrane tubules

Mani, Muralidharan,Lee, Unn Hwa,Yoon, Nal Ae,Yoon, Eun Hye,Lee, Byung Ju,Cho, Wha Ja,Park, Jeong Woo Elsevier 2017 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>Previously we have reported that developmentally regulated GTP-binding protein 2 (DRG2) localizes on Rab5 endosomes and plays an important role in transferrin (Tfn) recycling. We here identified DRG2 as a key regulator of membrane tubule stability. At 30 min after Tfn treatment, DRG2 localized to membrane tubules which were enriched with phosphatidylinositol 4-monophosphate [PI(4)P] and did not contain Rab5. DRG2 interacted with Rac1 more strongly with GTP-bound Rac1 and tubular localization of DRG2 depended on Rac1 activity. DRG2 depletion led to destabilization of membrane tubules, while ectopic expression of DRG2 rescued the stability of the membrane tubules in DRG2-depleted cells. Our results reveal a novel mechanism for regulation of membrane tubule stability mediated by DRG2.</P> <P><B>Highlights</B></P> <P> <UL> <LI> DRG2 localizes to membrane tubules enriched with PI(4)P. </LI> <LI> Tubular localization of DRG2 depends on Rac1 activity. </LI> <LI> DRG2 depletion destabilizes membrane tubules. </LI> <LI> Overexpression of DRG2 rescued the stability of membrane tubules in DRG2 depleted cells. </LI> </UL> </P>

Overexpression of developmentally regulated GTP-binding protein-2 increases bone loss

Ke, Ke,Sul, Ok-Joo,Kim, Woon-Ki,Lee, Mi-Hyun,Ko, Myung-Seok,Suh, Jae-Hee,Kim, Hyun-Ju,Kim, Shin-Yoon,Park, Jeong-Woo,Choi, Hye-Seon American Physiological Society 2013 AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND M Vol.304 No.7

<P>The developmentally regulated GTP-binding protein-2 (DRG2) is a novel subclass of GTP-binding proteins. Many functional characteristics of osteoclasts (OC) are associated with small GTPases. We hypothesized that DRG2 affects bone mass via modulating OC activity. Using DRG2 transgenic mice, we investigated the role of DRG2 in bone remodeling. DRG2 overexpression caused a decrease in bone mass and an increase in the number and activity of OC in vivo. DRG2 overexpression increased fusion, spreading, survival, and resorption activity of OC in vitro<I>.</I> Downregulation of DRG2 by siRNA decreased fusion, spreading, and survival of OC, supporting the observations found in DRG2 transgenic OC. Transgenic mature OCs were larger, with actin rings and higher ERK, Akt, Rac1 and Rho activities than wild-type OCs. Inhibition of these proteins abolished the effects of DRG2 on formation of large OCs with actin rings, implying that DRG2 affects cytoskeleton reorganization in a Rac1/Rho/ERK/Akt-dependent manner. In summary, DRG2 is associated with survival and cytoskeleton organization of OC under influence of macrophage colony-stimulating factor, and its overexpression leads to elevated bone resorptive activity of OC, resulting in bone loss.</P>

DRG2 Regulates G2/M Progression via the Cyclin B1-Cdk1 Complex

장수화,김아람,박능화,박정우,한인섭 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.9

Developmentally regulated GTP-binding protein 2 (DRG2) plays an important role in cell growth. Here we explored the linkage between DRG2 and G2/M phase checkpoint function in cell cycle progression. We observed that knockdown of DRG2 in HeLa cells affected growth in a wound-healing assay, and tumorigenicity in nude mice xenografts. Flow cytometry assays and [3H] incorporation assays indicated that G2/M phase arrest was responsible for the decreased proliferation of these cells. Knockdown of DRG2 elicited down-regulation of the major mitotic promoting factor, the cyclin B1/Cdk1 complex, but up-regulation of the cell cycle arresting proteins, Wee1, Myt1, and p21. These findings identify a novel role of DRG2 in G2/M progression.

DRG2 Deficiency Causes Impaired Microtubule Dynamics in HeLa Cells

Thao Dang,장수화,백성훈,박정우,한인섭 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.12

The developmentally regulated GTP binding protein 2 (DRG2) is involved in the control of cell growth and differentiation. Here, we demonstrate that DRG2 regulates microtubule dynamics in HeLa cells. Analysis of live imaging of the plus-ends of microtubules with EB1-EGFP showed that DRG2 deficiency (shDRG2) significantly reduced the growth rate of HeLa cells. Depletion of DRG2 increased ‘slow and long-lived’ subpopulations, but decreased ‘fast and short-lived’ subpopulations of microtubules. Microtubule polymerization inhibitor exhibited a reduced response in shDRG2 cells. Using immunoprecipitation, we show that DRG2 interacts with tau, which regulates microtubule polymerization. Collectively, these data demonstrate that DRG2 may aid in affecting microtubule dynamics in HeLa cells.

DRG2 Regulates G2/M Progression via the Cyclin B1-Cdk1 Complex

Jang, Soo Hwa,Kim, Ah-Ram,Park, Neung-Hwa,Park, Jeong Woo,Han, In-Seob Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.9

Developmentally regulated GTP-binding protein 2 (DRG2) plays an important role in cell growth. Here we explored the linkage between DRG2 and G2/M phase checkpoint function in cell cycle progression. We observed that knockdown of DRG2 in HeLa cells affected growth in a wound-healing assay, and tumorigenicity in nude mice xenografts. Flow cytometry assays and [$^3H$] incorporation assays indicated that G2/M phase arrest was responsible for the decreased proliferation of these cells. Knockdown of DRG2 elicited down-regulation of the major mitotic promoting factor, the cyclin B1/Cdk1 complex, but upregulation of the cell cycle arresting proteins, Wee1, Myt1, and p21. These findings identify a novel role of DRG2 in G2/M progression.

R-type Calcium Channel Isoform in Rat Dorsal Root Ganglion Neurons

Zhi Fang,황재홍,김종수,정성준,오석배 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.1

R-type Cav2.3 high voltage-activated Ca2+ channels in peripheral sensory neurons contribute to pain transmission. Recently we have demonstrated that, among the six Cav2.3 isoforms (Cav2.3a∼Cav2.3e), the Cav2.3e isoform is primarily expressed in trigeminal ganglion (TG) nociceptive neurons. In the present study, we further investigated expression patterns of Cav2.3 isoforms in the dorsal root ganglion (DRG) neurons. As in TG neurons, whole tissue RT-PCR analyses revealed the presence of two isoforms, Cav2.3a and Cav2.3e, in DRG neurons. Single-cell RT-PCR detected the expression of Cav2.3e mRNA in 20% (n=14/70) of DRG neurons, relative to Cav2.3a expression in 2.8% (n=2/70) of DRG neurons. Cav2.3e mRNA was mainly detected in small-sized neurons (n=12/14), but in only a few medium-sized neurons (n=2/14) and not in large-sized neurons, indicating the prominence of Cav2.3e in nociceptive DRG neurons. Moreover, Cav2.3e was preferentially expressed in tyrosine-kinase A (trkA)-positive, isolectin B4 (IB4)-negative and transient receptor potential vanilloid 1 (TRPV1)-positive neurons. These results suggest that Cav2.3e may be the main R-type Ca2+ channel isoform in nociceptive DRG neurons and thereby a potential target for pain treatment, not only in the trigeminal system but also in the spinal system.

R-type Calcium Channel Isoform in Rat Dorsal Root Ganglion Neurons

Fang, Zhi,Hwang, Jae-Hong,Kim, Joong-Soo,Jung, Sung-Jun,Oh, Seog-Bae The Korean Society of Pharmacology 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.1

R-type $Ca_v2.3$ high voltage-activated $Ca^{2+}$ channels in peripheral sensory neurons contribute to pain transmission. Recently we have demonstrated that, among the six $Ca_v2.3$ isoforms ($Ca_v2.3a{\sim}Ca_v2.3e$), the $Ca_v2.3e$ isoform is primarily expressed in trigeminal ganglion (TG) nociceptive neurons. In the present study, we further investigated expression patterns of $Ca_v2.3$ isoforms in the dorsal root ganglion (DRG) neurons. As in TG neurons, whole tissue RT-PCR analyses revealed the presence of two isoforms, $Ca_v2.3a$ and $Ca_v2.3e$, in DRG neurons. Single-cell RT-PCR detected the expression of $Ca_v2.3e$ mRNA in 20% (n=14/70) of DRG neurons, relative to $Ca_v2.3a$ expression in 2.8% (n=2/70) of DRG neurons. $Ca_v2.3e$ mRNA was mainly detected in small-sized neurons (n=12/14), but in only a few medium-sized neurons (n=2/14) and not in large-sized neurons, indicating the prominence of $Ca_v2.3e$ in nociceptive DRG neurons. Moreover, $Ca_v2.3e$ was preferentially expressed in tyrosine-kinase A (trkA)-positive, isolectin B4 (IB4)-negative and transient receptor potential vanilloid 1 (TRPV1)-positive neurons. These results suggest that $Ca_v2.3e$ may be the main R-type $Ca^{2+}$ channel isoform in nociceptive DRG neurons and thereby a potential target for pain treatment, not only in the trigeminal system but also in the spinal system.

Oxidation of extracellular cysteines by mercury chloride reduces TRPV1 activity in rat dorsal root ganglion neurons

Jin, Yun-Ju,Park, Jin-Young,Kim, Jun,Kwak, Ji-Yeon The Korean Society for Integrative Biology 2011 Animal cells and systems Vol.15 No.3

Transient receptor potential vanilloid type 1 (TRPV1) receptor plays an important role as a molecular detector of noxious signals in primary sensory neurons. Activity of TRPV1 can be modulated by the change in the environment such as redox state and extracellular cations. In the present study, we investigated the effect of the mercury chloride ($HgCl_2$) on the activity of TRPV1 in rat dorsal root ganglia (DRG) neurons using whole-cell patch clamp technique. Extracellular $HgCl_2$ reversibly reduced the magnitudes of capsaicin-activated currents ($I_{cap}$) in DRG neurons in a dose-dependent manner. The blocking effect of $HgCl_2$ was prevented by pretreatment with the reducing agent dithiothreitol (DTT). Inhibition of $I_{cap}$ by $HgCl_2$ was abolished by point mutation of individual cysteine residues located on the extracellular surface of TRPV1. These results suggest that three extracellular cysteines of TRPV1, Cys616, Cys634 and Cys621, are responsible for the oxidative modulation of $I_{cap}$ by $HgCl_2$.

Effects of Oriental Medicinal Drugs on Axonal Regeneration in the Spinal Cord Neurons

An Joung-Jo,NamGung Uk,Seo In-Chan,Kim Yoon-Sik The Physiological Society of Korean Medicine and T 2005 동의생리병리학회지 Vol.19 No.6

An oriental medicinal drugs Jahageo (JHG, Hominis placenta) were examined to determine its effects on the responsiveness of central nervous system neurons after injury. We found that JHG was involved in neurite outgrowth of DRG sensory axons. JHG treatment also increased expression of axonal growth-associated protein GAP-43 in DRG sensory neurons after sciatic nerve injury and in the injured spinal cord. JHG treatment during the spinal cord injury increased induction levels of cell division cycle 2 (Cdc2) protein in DRG as well as in the spinal cord. Histochemical investigation showed that induced Cdc2 in the injured spinal cord was found in non-neuronal cells. These results suggest that JHG regulates activities of non-neuronal cells such as oligodendrocyte and astrocyte in responses to spinal cord injury and protects neuronal responsiveness after axonal damage.