Suppression of androgen receptor signaling induces prostate cancer migration via activation of the CCL20-CCR6 axis.

The suppression of androgen receptor (AR) expression exacerbates the migration potential of prostate cancer. This study identified a previously unrecognized regulation of the AR-controlled pathway that promotes migration potential in prostate cancer cells. Prostate cancer cells that pass through a transwell membrane (mig cells) have a higher migration potential with a decreased AR expression than parental cells. In this study, we aimed to elucidate the mechanism of migration enhancement associated with the suppression of AR signaling. Expression of C-C motif ligand 20 (CCL20) is upregulated in mig cells, unlike in the parental cells. Knockdown of AR with small interfering RNA (siAR) in LNCaP and C4-2B cells increased CCL20 secretion and enhanced the migration of cancer cells. Mig cells, CCL20-treated cells, and siAR cells promoted cell migration with an enhancement of AKT phosphorylation and Snail expression, while the addition of a C-C chemokine receptor 6 (CCR6, the specific receptor of CCL20) inhibitor, anti-CCL20 antibody, and AKT inhibitor suppressed the activation of AKT and Snail. With 59 samples of prostate cancer tissue, CCL20 secretion was profuse in metastatic cases despite low AR expression levels. Snail expression was associated with the expression of CCL20 and CCR6. A xenograft study showed that the anti-CCL20 antibody significantly inhibited Snail expression, thereby suggesting a new therapeutic approach for castration-resistant prostate cancer with the inhibition of the axis between CCL20 and CCR6.

CCL2 induces resistance to the antiproliferative effect of cabazitaxel in prostate cancer cells.

Understanding the mechanism of chemoresistance and disease progression in patients with prostate cancer is important for developing novel treatment strategies. In particular, developing resistance to cabazitaxel is a major challenge in patients with docetaxel-resistant and castration-resistant prostate cancer (CRPC) because cabazitaxel is often administered as a last resort. However, the mechanism by which cabazitaxel resistance develops is still unclear. C-C motif chemokine ligands (CCL) were shown to contribute to the castration resistance of prostate cancer cells via an autocrine mechanism. Therefore, we focused on CCL as key factors of chemoresistance in prostate cancer cells. We previously established a cabazitaxel-resistant cell line, DU145-TxR/CxR, from a previously established paclitaxel-resistant cell line, DU145-TxR. cDNA microarray analysis revealed that the expression of CCL2 was upregulated in both DU145-TxR and DU145-TxR/CxR cells compared with DU145 cells. The secreted CCL2 protein level in DU145-TxR and DU145-TxR/CxR cells was also higher than in parental DU145 cells. The stimulation of DU145 cells with CCL2 increased the proliferation rate under treatments with cabazitaxel, and a CCR2 (a specific receptor of CCL2) antagonist suppressed the proliferation of DU145-TxR and DU145-TxR/CxR cells under treatments of cabazitaxel. The CCL2-CCR2 axis decreased apoptosis through the inhibition of caspase-3 and poly(ADP-ribose) polymerase (PARP). CCL2 is apparently a key contributor to cabazitaxel resistance in prostate cancer cells. Inhibition of the CCL2-CCR2 axis may be a potential therapeutic strategy against chemoresistant CRPC in combination with cabazitaxel.

Coffee diterpenes kahweol acetate and cafestol synergistically inhibit the proliferation and migration of prostate cancer cells.

BACKGROUND: Coffee inhibits the progression of prostate cancer; however, the direct mechanism through which coffee acts on prostate cancer cells remains unclear. This study aimed to identify the key compounds of coffee that possess anti-cancer effects and to investigate their mechanisms of action. METHODS: The anti-proliferation and anti-migration effects of six potentially active types of coffee compounds, including kahweol acetate, cafestol, caffeine, caffeic acid, chlorogenic acid, and trigonelline hydrochloride, were evaluated using LNCaP, LNCaP-SF, PC-3, and DU145 human prostate cancer cells. The synergistic effects of these compounds were also investigated. Apoptosis-related and epithelial-mesenchymal transition-related proteins, androgen receptor in whole cell and in nucleus, and chemokines were assessed. A xenograft study of SCID mice was performed to examine the in vivo effect of coffee compounds. RESULTS: Among the evaluated compounds, only kahweol acetate and cafestol inhibited the proliferation and migration of prostate cancer cells in a dose-dependent manner. The combination treatment involving kahweol acetate and cafestol synergistically inhibited proliferation and migration (combination index <1) with the induction of apoptosis, the inhibition of epithelial-mesenchymal transition, and decrease in androgen receptor, resulting in the reduction of nuclear androgen receptor in androgen receptor-positive cells. Moreover, kahweol acetate and cafestol downregulated CCR2 and CCR5 without an increase in their ligands, CCL2 and CCL5. The xenograft study showed that oral administration of kahweol acetate and cafestol significantly inhibited tumor growth. CONCLUSION: Kahweol acetate and cafestol synergistically inhibit the progression of prostate cancer. These coffee compounds may be novel therapeutic candidates for prostate cancer.

Tumor necrosis factor-α induces prostate cancer cell migration in lymphatic metastasis through CCR7 upregulation.

Understanding the mechanism of lymph node metastasis, a poor prognostic sign for prostate cancer, and the further dissemination of the disease is important to develop novel treatment strategies. Recent studies have reported that C-C chemokine receptor 7 (CCR7), whose ligand is CCL21, is abundantly expressed in lymph node metastasis and promotes cancer progression. Tumor necrosis factor-α (TNF-α) is chronically produced at low levels within the tumor microenvironment. The aim of this study was to determine whether TNF-α promotes prostate cancer dissemination from metastatic lymph nodes through activation of the CCL21/CCR7 axis. First, human prostate cancer cells were determined to express both TNF-α and CCR7. Second, low concentrations of TNF-α were confirmed to induce CCR7 in prostate cancer cells through phosphorylation of ERK. Finally, CCL21 was found to promote the migration of prostate cancer cells through phosphorylation of the protein kinase p38. Our results suggest that TNF-α leads to the induction of CCR7 expression and that the CCL21/CCR7 axis might increase the metastatic potential of prostate cancer cells in lymph node metastasis.

C-C motif ligand 5 promotes migration of prostate cancer cells in the prostate cancer bone metastasis microenvironment.

Chemokines and their receptors have key roles in cancer progression. The present study investigated chemokine activity in the prostate cancer bone metastasis microenvironment. Growth and migration of human prostate cancer cells were assayed in cocultures with bone stromal cells. The migration of LNCaP cells significantly increased when co-cultured with bone stromal cells isolated from prostate cancer bone metastases. Cytokine array analysis of conditioned medium from bone stromal cell cultures identified CCL5 as a concentration-dependent promoter of LNCaP cell migration. The migration of LNCaP cells was suppressed when C-C motif ligand 5 (CCL5) neutralizing antibody was added to cocultures with bone stromal cells. Knockdown of androgen receptor with small interfering RNA increased the migration of LNCaP cells compared with control cells, and CCL5 did not promote the migration of androgen receptor knockdown LNCaP. Elevated CCL5 secretion in bone stromal cells from metastatic lesions induced prostate cancer cell migration by a mechanism consistent with CCL5 activity upstream of androgen receptor signaling.

Quick, Selective and Reversible Photocrosslinking Reaction between 5-Methylcytosine and 3-Cyanovinylcarbazole in DNA Double Strand.

Selective photocrosslinking reaction between 3-cyanovinylcarbazole nucleoside (CNVK) and 5-methylcytosine (mC), which is known as epigenetic modification in genomic DNA, was developed. The reaction was completely finished within 5 s of 366 nm irradiation, and the rate of this photocrosslinking reaction was ca. 30-fold higher than that in the case of unmodified normal cytosine. There were no significant differences in the thermodynamic parameters and the kinetics of hybrid formation of oligonucleotide (ODN) containing CNVK and its complementary ODN containing C or mC at the photocrosslinking site, and suggesting that the quick and selective photoreaction has potential for the selective detection of mC in the DNA strand via the photocrosslinking reaction.

The CCL2-CCR2 Axis Contributes to Migration of Cabazitaxel-resistant Prostate Cancer Cells.

BACKGROUND/AIM: Developing resistance to cabazitaxel is a major challenge in patients with docetaxel- and castration-resistant prostate cancer (CRPC) since it is frequently administered as a last resort. We have previously reported that CCL2 induces resistance to the antiproliferative effect of cabazitaxel in DU145-TxR/CxR prostate cancer cell lines. However, how CCL2 induces resistance to the antimigration effect of cabazitaxel remains unclear. MATERIALS AND METHODS: We established a cabazitaxel-resistant cell line, DU145-TxR/CxR, from a previously established paclitaxel-resistant cell line, DU145-TxR, which was confirmed to show docetaxel resistance. We performed migration assay and analyzed the expression of epithelial-mesenchymal transition markers using DU145-TxR/CxR with or without CCL2 silencing with small interfering RNA (siRNA) transfection. RESULTS: Cabazitaxel inhibited the migration of DU145 cells through the inactivation of STAT3. A CCR2 (a specific receptor of CCL2) antagonist suppressed the migration of DU145-TxR and DU145-TxR/CxR cells under cabazitaxel treatment. Western blotting revealed that the CCR2 antagonist inhibited STAT3 phosphorylation in DU145-TxR and DU145-TxR/CxR cells under cabazitaxel treatment. CCL2 silencing with siRNA in DU145-TxR and DU145-TxR/CxR cells decreased migration through STAT3 and p38 inactivation. Furthermore, CCL2 activated AKT, and CCR2 antagonist inhibited AKT phosphorylation in DU145-TxR and DU145-TxR/CxR cells with recovery of sensitivity to cabazitaxel under cabazitaxel treatment. CONCLUSION: The CCL2-CCR2 axis is a key contributor to resistance to the antimigration effect of cabazitaxel in prostate cancer cells. CCL2-CCR2 axis inhibition may be a potential therapeutic target against chemoresistant CRPC in combination with cabazitaxel.

Anti-proliferative and anti-migratory properties of coffee diterpenes kahweol acetate and cafestol in human renal cancer cells.

Despite improvements in systemic therapy options for renal cancer, it remains one of the most drug-resistant malignancies. Interestingly, reports have shown that kahweol and cafestol, natural diterpenes extracted from coffee beans, exhibit anti-cancer activity. However, the multiple potential pharmacological actions of both have yet to be fully understood. This study therefore investigated the effects of kahweol acetate and cafestol on human renal cancer ACHN and Caki-1 cells. Accordingly, the combination of kahweol acetate and cafestol administration synergistically inhibited cell proliferation and migration by inducing apoptosis and inhibiting epithelial-mesenchymal transition. Mechanistic dissection revealed that kahweol acetate and cafestol inhibited Akt and ERK phosphorylation. Moreover, kahweol acetate and cafestol downregulated the expression of not only C-C chemokine receptors 2, 5, and 6 but also programmed death-ligand 1, indicating their effects on the tumor microenvironment. Thus, kahweol acetate and cafestol may be novel therapeutic candidates for renal cancer considering that they exert multiple pharmacological effects.

Reply to Comment on "Kadomoto, S. et al. Tumor-Associated Macrophages Induce Migration of Renal Cell Carcinoma Cells via Activation of the CCL20-CCR6 Axis" Cancers 2020 12, 89.

We appreciate Zins and Abraham [1] commenting on our paper studying the role of the CCL20-CCR6 axis on renal cell carcinoma (RCC) cells [2]. As they pointed out, our study has certain limitations. Although M1- and M2-types cannot be separated clearly and a consecutive change of character might exist between them, it has been reported that plural specific markers express on M1- and M2-types. Unfortunately, a definite difference between M1 and M2 macrophages was not confirmed in our study. For more differentiation, multiple stimulations, such as suggested in the comments of Zins and Abraham, might be needed. Hence, we needed to expediently use "M1-like" and "M2-like" to mention specific status of these macrophage-like cells. Meanwhile, CCL20 expression levels of M2-like-THP-1 cells co-cultured with RCC cells were dramatically increased compared with parental THP-1 cells, indicating that certain stimulations within the tumor microenvironment rather than theoretical stimulations make macrophages differentiated; however, further studies are needed to clarify this mechanism using a more appropriate co-culture system mimicking the tumor microenvironment. Immunohistochemistry of CCL20 and M2 markers will help to better understand the role of tissue infiltrating macrophages, even tissue CD68 staining intensity itself was reported to correlate with prognosis of RCC patients [3]. [...].

Tumor-Associated Macrophages Induce Migration of Renal Cell Carcinoma Cells via Activation of the CCL20-CCR6 Axis.

This study investigated tumor-associated macrophages activity in the microenvironment of renal cell carcinoma. Via a co-culture with macrophage-like cells differentiated from human monocyte cell line THP-1 and U937 cells, the migration ability of ACHN and Caki-1 cells, which are human renal cell carcinoma cell line cells, was significantly increased, as was the epithelial-mesenchymal transition change. A chemokine array identified the CCL20-CCR6 axis as a concentration-dependent signal in ACHN and Caki-1 cell migration. Akt in the ACHN and Caki-1 cells was activated by macrophage-like cells, and the CCL20 neutralizing antibody suppressed migration ability, epithelial-mesenchymal transition, and Akt phosphorylation in the ACHN and Caki-1 cells. Akt inhibitor AZD5363 also decreased the epithelial-mesenchymal transition change and migration ability in the ACHN and Caki-1 cells. In 42 renal cell carcinoma tissues, patients with CCR6 and macrophage infiltration indicated poor prognoses. In the tumor microenvironment of renal cell carcinoma, cancer cells are activated by CCL20 secreted by tumor-associated macrophages through Akt activation, followed by epithelial-mesenchymal transition and an acquired migration ability. Thus, inhibition of the CCL20-CCR6 axis may be a potential therapeutic strategy for renal cell carcinoma.

Site-specific photochemical RNA editing.

Photo-induced artificial RNA editing was demonstrated using photo-reactive oligonucleotides containing 3-cyanovinylcarbazole nucleoside. This non-enzymatic and sequence-specific methodology will make a major contribution to the elucidation of RNA functions including non-coding RNAs and to the development of drugs based on sequence-specific RNA editing.