Involvement of DKK1 secreted from adipose-derived stem cells in alopecia areata.

Adipose-derived stem cells (ASCs) have shown efficacy in promoting hair growth, while DKK1 inhibits the WNT pathway, which is associated with hair loss. Our study focused on investigating the expression of DKK1 in alopecia areata (AA), a condition characterised by significant increases in the DKK1 levels in human and mouse ASCs. Treatment of interferon-γ increased the expression of DKK1 via STAT3 phosphorylation in ASCs. Treatment with recombinant DKK1 resulted in a decrease of cell growth in outer root sheath cells, whereas the use of a DKK1 neutralising antibody promoted hair growth. These results indicate that ASCs secrete DKK1, playing a crucial role in the progression and development of AA. Consequently, we generated DKK1 knockout (KO) ASCs using the Crispr/Cas9 system and evaluated their hair growth-promoting effects in an AA model. The DKK1 KO in ASCs led to enhanced cell motility and reduced cellular senescence by activating the WNT signalling pathway, while it reduced the expression of inflammatory cytokines by inactivating the NF-kB pathway. As expected, the intravenous injection of DKK1-KO-ASCs in AA mice, and the treatment with a conditioned medium derived from DKK1-KO-ASCs in hair organ culture proved to be more effective compared with the use of naïve ASCs and their conditioned medium. Overall, these findings suggest that DKK1 represents a novel therapeutic target for treating AA, and cell therapy using DKK1-KO-ASCs demonstrates greater efficiency.

Effects of the Complex of Panicum miliaceum Extract and Triticum aestivum Extract on Hair Condition.

Proso millet (Panicum miliaceum L.) and common wheat (Triticum aestivum L.) have been used as major crops in multiple regions since ancient times, and they contain various nutrients that can affect human hair health. This study investigated the various biological effects of a complex of millet extract and wheat extract (MWC) on hair health. Human immortalized dermal papilla cells (iDPCs) for an in vitro study and an anagen-synchronized mouse model for an in vivo study were employed. These findings revealed that the application of the MWC in vitro led to an increase in the mRNA levels of antioxidant enzymes (catalase and SOD1), growth factors (IGF-1, VEGF, and FGF7), and factors related to hair growth (wnt10b, ß-catenin) while decreasing inflammatory cytokine mRNA levels (IL-6 and TNFα). The mRNA levels of hair follicles (HFs) in the dorsal skin of the mouse model in the early and late telogen phases were also measured. The mRNA levels in the in vivo study showed a similar alteration tendency as in the in vitro study in the early and late telogen phases. In this model, MWC treatment elongated the anagen phase of the hair cycle. These findings indicate that the MWC can suppress oxidative stress and inflammation and may elongate the anagen phase by enhancing the growth factors involved in the wnt10b/ß-catenin signaling pathway. This study suggests that the MWC might have significant potential as a functional food for maintaining hair health.

Dermal Papilla Cell Proliferation of Phytochemicals Isolated from Chestnut Shells (Castanea crenata).

Castanea crenata (Fagaceae) is a species of chestnut tree that is endemic to the Republic of Korea and Japan. While its kernels are consumed, chestnut by-products such as shells and burs, which account for 10-15% of the total weight, are discarded as waste. Phytochemical and biological studies have been carried out to eliminate this waste and develop high-value products from its by-products. In this study, five new compounds (1-2, 6-8) along with seven known compounds were isolated from the shell of C. crenata. This is the first study to report diterpenes from the shell of C. crenata. Comprehensive spectroscopic data including 1D, 2D NMR, and CD spectroscopy were used to determine the compound structures. All isolated compounds were examined for their ability to stimulate dermal papilla cell proliferation using a CCK-8 assay. In particular, 6ß,7ß,16α,17-Tetrahydroxy-ent-kauranoic acid, isopentyl-α-L-arabinofuranosyl-(1→6)-ß-D-glucopyranoside, and ellagic acid exhibited the most potent proliferation activity of all.

CXCL12 inhibits hair growth through CXCR4.

CXCL12 and its receptors, which are highly expressed in the skin, are associated with various cutaneous diseases, including androgenic alopecia. However, their expression and role during the hair cycle are unknown. This study aims to investigate the expression of CXCL12 and its receptor, CXCR4, in the vicinity of hair follicles and their effect on hair growth. CXCL12 was highly expressed in dermal fibroblasts (DFs) and its level was elevated throughout the catagen and telogen phases of the hair cycle. CXCR4 is expressed in the dermal papilla (DP) and outer root sheath (ORS). In hair organ culture, hair loss was induced by recombinant CXCL12 therapy, which delayed the telogen-to-anagen transition and decreased hair length. In contrast, the suppression of CXCL12 using a neutralizing antibody and siRNA triggered the telogen-to-anagen transition and increased hair length in hair organ culture. Neutralization of CXCR7, one of the two receptors for CXCL12, only slightly affected hair growth. However, inhibition of CXCR4, the other receptor for CXCL12, increased hair growth to a considerable extent. In addition, in hair organ culture, the conditioned medium from DFs with CXCL12 siRNA considerably increased the hair length and induced proliferation of DP and ORS cells. CXCL12, through CXCR4 activation, increased STAT3 and STAT5 phosphorylation in DP and ORS cells. In contrast, blocking CXCL12 and CXCR4 decreased the phosphorylation of STAT3 and STAT5. In summary, these findings suggest that CXCL12 inhibits hair growth via the CXCR4/STAT signaling pathway and that CXCL12/CXCR4 pathway inhibitors are a promising treatment option for hair growth.

TGF-ß2 and collagen play pivotal roles in the spheroid formation and anti-aging of human dermal papilla cells.

Dermal papilla cells (DPCs) tend to aggregate both in vitro and in vivo, which increases the hair inductivity of DPCs. However, the underlying mechanism of spheroid formation is unknown. We investigated whether collagen expression in human DPCs (hDPCs) is involved in the spheroid formation and hair inductivity of hDPCs and further examined the underlying molecular mechanism of collagen upregulation. The expression of diverse collagens, such as COL13A1 and COL15A1, was upregulated in three dimensional (3D)-cultured or intact DPCs, compared to 2D-cultured hDPCs. This collagen expression was a downregulated in aged hair follicle, and aged DPCs were difficult to aggregate. Blocking of COL13A1 and COL15A1 by small interfering RNA reduced aggregation, while induced senescence of hDPCs in vitro. Further, transforming growth factor-ß2 (TGF-ß2) expression decreases with aging, and is involved in regulating the expression of COL13A1 and COL15A1. Addition of recombinant TGF-ß2 delayed cellular senescence, and recovered spheroid formation in aged hDPCs by upregulating collagen levels. On the contrary, knock-out of TGF-ß2 induced the aging of DPCs, and inhibited spheroid formation. These results suggested that COL13A1 and COL15A1 expression is downregulated with aging in DPCs, and upregulation of collagen by TGF-ß2 induces the spheroid formation of DPCs. Therefore, TGF-ß2 supplement in DPC culture medium could enhance the maintenance and hair inductivity of DPCs.

Hair Growth Promotion by δ-Opioid Receptor Activation.

Literature has revealed that the delta opioid receptor (DOR) exhibited diverse pharmacological effects on neuron and skin. In the present study, we have investigated whether the activation of DOR has hair-growth promotion effects. Compared with other opioid receptor, DOR was highly expressed in epidermal component of hair follicle in human and rodents. The expression of DOR was high in the anagen phase, but it was low in the catagen and telogen phases during mouse hair cycle. Topical application of UFP-512, a specific DOR agonist, significantly accelerated the induction of the anagen in C3H mice. Topical application of UFP-512 also increased the hair length in hair organ cultures and promoted the proliferation and the migration of outer root sheath (ORS) cells. Similarly, pharmacological inhibition of DOR by naltrindole significantly inhibited the anagen transition process and decreased hair length in hair organ cultures. Thus, we further examined whether Wnt/ß-catenin pathway was related to the effects of DOR on hair growth. We found that Wnt/ß-catenin pathway was activated by UFP-512 and siRNA for ß-catenin attenuated the UFP-512 induced proliferation and migration of ORS cells. Collectively, result established that DOR was involved in hair cycle regulation, and that DOR agonists such as UFP-512 should be developed for novel hair-loss treatment.

Marliolide Derivative Induces Melanosome Degradation via Nrf2/p62-Mediated Autophagy.

Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.

Hair growth promotion by necrostatin-1s.

Necrostatins (Necs) have been developed as a receptor-interacting protein kinase 1 (RIPK1) inhibitor, thus inhibiting necroptosis. In this current study, we have investigated the possible involvement of necroptosis in the hair cycle regulation and further examined its underlying molecular mechanisms. Diverse RIPK1/3 inhibitors and siRNA were tested in the human outer-root sheath (ORS) cells and animal models. The expression and hair cycle-dependent expression of RIPK 1, respectively, were investigated in the hair follicles (HF) of human, pig, and the mouse. Resulting from the experiment, Nec-1s was most effective in the hair growth promotion among several inhibitors. Nec-1s induced the ORS cell proliferation and migration, and increased the HF length in mouse and pig organ cultures. In addition, it accelerated the telogen-to-anagen transition and elongated the anagen period in the mouse model. Both apoptosis and necroptosis were detected in hair cycle. RIPK1 and RIPK3 were highly expressed in ORS cells during the hair regression period. Nec-1s upregulated the mRNA expression of Wnt3a and Wnt5b, and the activity of ß-catenin. Collectively, Nec-1s promotes hair growth through inhibiting necroptosis and activating the Wnt/ß-catenin pathway. Necroptosis is involved in hair cycle regression, and Nec-1s is a promising target for hair-loss treatment.

Inhibition of Rab27a and Rab27b Has Opposite Effects on the Regulation of Hair Cycle and Hair Growth.

Rab27a/b are known to play an important role in the transport of melanosomes, with their knockout causing silvery gray hair. However, the relationship between Rab27a/b and hair growth is not well known. To evaluate the role of Rab27a/b in hair cycle, we investigated the expression of Rab27a/b during hair cycling and human outer root sheath (hORS) cells. The expression of Rab27a in ORS cells was mainly detected at the anagen, whereas expression of Rab27b in ORS, and epidermal cells was strongly expressed at the telogen. Additionally, Rab27a/b were expressed in the Golgi of hORS cells. To evaluate the role of Rab27a/b in hair growth, telogen-to-anagen transition animal and vibrissae hair follicles (HFs) organ culture models were assayed using Rab27a/b siRNAs. The knockdown of Rab27a or Rab27b suppressed or promoted hair growth, respectively. These results were also confirmed in human dermal papilla cells (hDPCs) and hORS cells, showing the opposite mitogenic effects. Moreover, Rab27b knockdown increased the expression levels of various growth factors in the hDPCs and hORS cells. Overall, the opposite temporal expression patterns during hair cycling and roles for hair growth of Rab27a/b suggested that Rab27a/b might regulate the hair cycle. Therefore, our study may provide a novel solution for the development of hair loss treatment by regulating Rab27a/b levels.

Epiregulin promotes hair growth via EGFR-medicated epidermal and ErbB4-mediated dermal stimulation.

OBJECTIVES: EREG (epiregulin), a member of the epidermal growth factor (EGF) family, plays a role in inflammation, wound healing, normal physiology and malignancies. However, little is known about its function on hair growth. MATERIALS AND METHODS: Cell growth assay, QPCR and immunostaining were carried out. Telogen-to-anagen transition and organ culture were conducted. ROS level was monitored by staining DCFDA. RESULTS: We investigated the hair inductive effect of EREG and the mechanism of stimulation on DPCs and ORS cells during hair cycling. Whereas EREG promoted hair growth, EREG knockdown inhibited hair growth as evidenced by telogen-to-anagen transition and organ culture models. EREG was expressed in epidermal cells including ORS cells in vivo. EREG activated phospho-ErbB4 in DPCs during hair cycling and stimulated DPCs via ErbB4 activation in vitro. In terms of the underlying mechanism, reactive oxygen species (ROS) played a key role in DPC stimulation. EREG also activated phospho-EGF receptor (EGFR) in epidermal cells including matrix and ORS cells in vivo and stimulated ORS cells via EGFR activation in vitro. CONCLUSIONS: EREG, which is released from ORS cells, activated EGFR and ErbB4 on epidermal cells and DPCs during hair cycling, respectively. As a result, EREG stimulated epidermal cells a positive feedback and DPCs via regulating ROS generation for hair growth. Therefore, EREG therapy may be a novel solution for hair loss treatment.

HB-EGF Improves the Hair Regenerative Potential of Adipose-Derived Stem Cells via ROS Generation and Hck Phosphorylation.

Although adipose-derived stem cells (ASCs) have hair regenerative potential, their hair inductive capabilities are limited. The mitogenic and hair inductive effects of heparin binding-epidermal growth factor-like growth factor (HB-EGF) on ASCs were investigated in this study and the underlying mechanism of stimulation was examined. Cell growth, migration, and self-renewal assays, as well as quantitative polymerase chain reactions and immunostaining, were carried out. Telogen-to-anagen transition and organ culture using vibrissa follicles were also conducted. HB-EGF significantly increased ASC motility, including cell proliferation, migration, and self-renewal activity. The preconditioning of ASCs with HB-EGF induced telogen-to-anagen transition more rapidly in vivo, and injected PKH26-ASCs survived for longer periods of time. Conditioned medium obtained from HB-EGF-treated ASCs promoted hair growth in vivo, upregulating growth factors. In particular, thrombopoietin (THPO) also induced hair growth in vivo, stimulating dermal papilla cells (DPCs). Reactive oxygen species (ROS) appeared to play a key role in ASC stimulation as the inhibition of ROS generation and NOX4 knockout attenuated ASC stimulation and THPO upregulation by HB-EGF. In addition, the Hck phosphorylation pathway mediated the stimulation of ASCs by HB-EGF. In summary, HB-EGF increased the motility and paracrine effects of ASCs releasing THPO growth factor and THPO promoted hair growth-stimulating DPCs. ROS generation and Hck phosphorylation are key factors in HB-EGF-induced ASC stimulation. Therefore, combination therapy involving HB-EGF and ASCs may provide a novel solution for hair-loss treatment.

Udenafil Induces the Hair Growth Effect of Adipose-Derived Stem Cells.

Udenafil, which is a PDE5 inhibitor, is used to treat erectile dysfunction. However, it is unclear whether udenafil induces hair growth via the stimulation of adipose-derived stem cells (ASCs). In this study, we investigated whether udenafil stimulates ASCs and whether increased growth factor secretion from ASCs to facilitate hair growth. We found that subcutaneous injection of udenafiltreated ASCs accelerated telogen-to-anagen transition in vivo. We also observed that udenafil induced proliferation, migration and tube formation of ASCs. It also increased the secretion of growth factors from ASCs, such as interleukin-4 (IL-4) and IL12B, and the phosphorylation of ERK1/2 and NFκB. Furthermore, concomitant upregulation of IL-4 and IL12B mRNA levels was attenuated by ERK inhibitor or NFκB knockdown. Application of IL-4 or IL12B enhanced anagen induction in mice and increased hair follicle length in organ culture. The results indicated that udenafil stimulates ASC motility and increases paracrine growth factor, including cytokine signaling. Udenafil-stimulated secretion of cytokine from ASCs may promote hair growth via the ERK and NFκB pathways. Therefore, udenafil can be used as an ASC-preconditioning agent for hair growth.

Src inhibition induces melanogenesis in human G361 cells.

The Src kinase family (SKF) includes non­receptor tyrosine kinases that interact with many cellular cytosolic, nuclear and membrane proteins, and is involved in the progression of cellular transformation and oncogenic activity. However, there is little to no evidence on the effect of SKF or its inhibitors on melanogenesis. Therefore, the present study investigated whether C­terminal Src kinase inhibition can induce melanogenesis and examined the associated signaling pathways and mRNA expression of melanogenic proteins. First, whether stimulators of melanogenesis, such as ultraviolet B and α­melanocyte­stimulating hormone, can dephosphorylate Src protein was evaluated, and the results revealed that SU6656 and PP2 inhibited the phosphorylation of Src in G361 cells. Src inhibition by these chemical inhibitors induced melanogenesis in G361 cells and upregulated the mRNA expression levels of melanogenesis­associated genes encoding microphthalmia­associated transcription factor, tyrosinase­related protein 1 (TRP1), TRP2, and tyrosinase. In addition, Src inhibition by small interfering RNA induced melanogenesis and upregulated the mRNA expression levels of melanogenesis­associated genes. As the p38 mitogen­activated protein kinase (MAPK) and cyclic adenosine monophosphate response element binding (CREB) pathways serve key roles in melanogenesis, the present study further examined whether Src mediates melanogenesis via these pathways. As expected, Src inhibition via SU6656 or PP2 administration induced the phosphorylation of p38 or CREB, as determined by western blotting analysis, and increased the levels of phosphorylated p38 or CREB, as determined by immunofluorescence staining. In addition, the induced pigmentation and melanin content of G361 cells by Src inhibitors was significantly inhibited by p38 or CREB inhibitors. Taken together, these data indicate that Src is associated with melanogenesis, and Src inhibition induces melanogenesis via the MAPK and CREB pathways in G361 cells.

Generation of trichogenic adipose-derived stem cells by expression of three factors.

BACKGROUND: Previous studies demonstrated that adipose-derived stem cells (ASCs) can promote hair growth, but unmet needs exist for enhancing ASC hair inductivity. OBJECTIVE: Therefore, we introduced three trichogenic factors platelet-derived growth factor-A, SOX2, and ß-catenin to ASCs (tfASCs) and evaluated whether tfASCs have similar characteristics as dermal papilla (DP) cells. METHOD: Global gene expression was examined using NGS analysis. Telogen-to-anagen induction, vibrissae hair follicle organ culture and patch assay were used. RESULTS: tfASC cell size is smaller than that of ASCs, and they exhibit short doubling time. tfASCs also resist aging and can be expanded until passage 12. Cell proportion in S and G2/M increases in tfASCs, and tfASCs express high mRNA levels of cell cycle related genes. The mRNA expression of DP markers was notably higher in tfASCs. Moreover, NGS analysis revealed that the global gene expression of tfASCs is similar to that of DP cells. The injection of tfASCs accelerated the telogen-to-anagen transition and conditioned medium of tfASCs increased the anagen phase of vibrissal hair follicles. Finally, we found that the injection of 3D-cultured tfASCs at p 9 generated new hair follicles in nude mice. CONCLUSION: Collectively, these results indicate that 1) tfASCs have similar characteristics as DP cells, 2) tfASCs have enhanced hair-regenerative potential compared with ASCs, and 3) tfASCs even at late passage can make new hair follicles in a hair reconstitution assay. Because DP cells are difficult to isolate/expand and ASCs have low hair inductivity, tfASCs and tfASC-CM are clinically good candidates for hair regeneration.

Minoxidil Promotes Hair Growth through Stimulation of Growth Factor Release from Adipose-Derived Stem Cells.

Minoxidil directly promotes hair growth via the stimulation of dermal papilla (DP) and epithelial cells. Alternatively, there is little evidence for indirect promotion of hair growth via stimulation of adipose-derived stem cells (ASCs). We investigated whether minoxidil stimulates ASCs and if increased growth factor secretion by ASCs facilitates minoxidil-induced hair growth. Telogen-to-anagen induction was examined in mice. Cultured DP cells and vibrissae hair follicle organ cultures were used to further examine the underlying mechanisms. Subcutaneous injection of minoxidil-treated ASCs accelerated telogen-to-anagen transition in mice, and increased hair weight at day 14 post-injection. Minoxidil did not alter ASC proliferation, but increased migration and tube formation. Minoxidil also increased the secretion of growth factors from ASCs, including chemokine (C-X-C motif) ligand 1 (CXCL1), platelet-derived endothelial cell growth factor (PD-ECGF), and platelet-derived growth factor-C (PDGF-C). Minoxidil increased extracellular signal-regulated kinases 1/2 (ERK1/2) phosphorylation, and concomitant upregulation of PD-ECGF and PDGF-C mRNA levels were attenuated by an ERK inhibitor. Subcutaneous injection of CXCL1, PD-ECGF, or PDGF-C enhanced anagen induction in mice, and both CXCL1 and PDGF-C increased hair length in ex vivo organ culture. Treatment with CXCL1, PD-ECGF, or PDGF-C also increased the proliferation index in DP cells. Finally, topical application of CXCL1, PD-ECGF, or PDGF-C with 2% minoxidil enhanced anagen induction when compared to minoxidil alone. Minoxidil stimulates ASC motility and increases paracrine growth factor signaling. Minoxidil-stimulated secretion of growth factors by ASCs may enhance hair growth by promoting DP proliferation. Therefore, minoxidil can be used as an ASC preconditioning agent for hair regeneration.

Development of S-Methylmethionine Sulfonium Derivatives and Their Skin-Protective Effect against Ultraviolet Exposure.

In a previous study, we have demonstrated that S-methylmethionine sulfonium (SMMS) confers wound-healing and photoprotective effects on the skin, suggesting that SMMS can be used as a cosmetic raw material. However, it has an unpleasant odor. Therefore, in the present study, we synthesized odor-free SMMS derivatives by eliminating dimethyl sulfide, which is the cause of the unpleasant odor and identified two derivatives that exhibited skin-protective effects: one derivative comprised (2S,4S)- and (2R,4S)-2-phenylthiazolidine-4-carboxylic acid and the other comprised (2S,4R)-, (2S,4S)-, (2R,4R)-, and (2R,4S)-2-phenyl-1,3-thiazinane-4-carboxylic acid. We performed in vitro proliferation assays using human dermal fibroblasts (hDFs) and an immortalized human keratinocyte cell line (HaCaT). The two SMMS derivatives were shown to increase hDF and HaCaT cell proliferation as well as improve their survival by protecting against ultraviolet exposure. Moreover, the derivatives regulated the expression of collagen type I and MMP mRNAs against ultraviolet exposure in hDFs, suggesting that these derivatives can be developed as cosmetic raw materials.

Single Cell Clones Purified from Human Parotid Glands Display Features of Multipotent Epitheliomesenchymal Stem Cells.

A better understanding of the biology of tissue-resident stem cell populations is essential to development of therapeutic strategies for regeneration of damaged tissue. Here, we describe the isolation of glandular stem cells (GSCs) from a small biopsy specimen from human parotid glands. Single colony-forming unit-derived clonal cells were isolated through a modified subfractionation culture method, and their stem cell properties were examined. The isolated clonal cells exhibited both epithelial and mesenchymal stem cell (MSC)-like features, including differentiation potential and marker expression. The cells transiently displayed salivary progenitor phenotypes during salivary epithelial differentiation, suggesting that they may be putative multipotent GSCs rather than progenitor cells. Both epithelial and mesenchymal-expressing putative GSCs, LGR5+CD90+ cells, were found in vivo, mostly in inter-secretory units of human salivary glands. Following in vivo transplantation into irradiated salivary glands of mice, these cells were found to be engrafted around the secretory complexes, where they contributed to restoration of radiation-induced salivary hypofunction. These results showed that multipotent epitheliomesenchymal GSCs are present in glandular mesenchyme, and that isolation of homogenous GSC clones from human salivary glands may promote the precise understanding of biological function of bona fide GSCs, enabling their therapeutic application for salivary gland regeneration.

miR-93/miR-106b/miR-375-CIC-CRABP1: a novel regulatory axis in prostate cancer progression.

Capicua (CIC) has been implicated in pathogenesis of spinocerebellar ataxia type-1 (SCA1) neurodegenerative disease and some types of cancer; however, the role of CIC in prostate cancer remains unknown. Here we show that CIC suppresses prostate cancer progression. CIC expression was markedly decreased in human prostatic carcinoma. CIC overexpression suppressed prostate cancer cell proliferation, invasion, and migration, whereas CIC RNAi exerted opposite effects. We found that knock-down of CIC derepresses expression of ETV5 and CRABP1 in LNCaP and PC-3 cells, respectively, thereby promoting cell proliferation and invasion. We also discovered that miR-93, miR-106b, and miR-375, which are known to be frequently overexpressed in prostate cancer patients, cooperatively down-regulate CIC levels to promote cancer progression. Altogether, we suggest miR-93/miR-106b/miR-375-CIC-CRABP1 as a novel key regulatory axis in prostate cancer progression.

Deficiency of Capicua disrupts bile acid homeostasis.

Capicua (CIC) has been implicated in pathogenesis of spinocerebellar ataxia type 1 and cancer in mammals; however, the in vivo physiological functions of CIC remain largely unknown. Here we show that Cic hypomorphic (Cic-L(-/-)) mice have impaired bile acid (BA) homeostasis associated with induction of proinflammatory cytokines. We discovered that several drug metabolism and BA transporter genes were down-regulated in Cic-L(-/-) liver, and that BA was increased in the liver and serum whereas bile was decreased within the gallbladder of Cic-L(-/-) mice. We also found that levels of proinflammatory cytokine genes were up-regulated in Cic-L(-/-) liver. Consistent with this finding, levels of hepatic transcriptional regulators, such as hepatic nuclear factor 1 alpha (HNF1α), CCAAT/enhancer-binding protein beta (C/EBPß), forkhead box protein A2 (FOXA2), and retinoid X receptor alpha (RXRα), were markedly decreased in Cic-L(-/-) mice. Moreover, induction of tumor necrosis factor alpha (Tnfα) expression and decrease in the levels of FOXA2, C/EBPß, and RXRα were found in Cic-L(-/-) liver before BA was accumulated, suggesting that inflammation might be the cause for the cholestasis in Cic-L(-/-) mice. Our findings indicate that CIC is a critical regulator of BA homeostasis, and that its dysfunction might be associated with chronic liver disease and metabolic disorders.