The HSP90 inhibitor HVH-2930 exhibits potent efficacy against trastuzumab-resistant HER2-positive breast cancer

Rationale: Resistance to targeted therapies like trastuzumab remains a critical challenge for HER2-positive breast cancer patients. Despite the progress of several N-terminal HSP90 inhibitors in clinical trials, none have achieved approval for clinical use, primarily due to issues such as induction of the heat shock response (HSR), off-target effects, and unfavorable toxicity profiles. We sought to examine the effects of HVH-2930, a novel C-terminal HSP90 inhibitor, in overcoming trastuzumab resistance. Methods: The effect of HVH-2930 on trastuzumab-sensitive and -resistant cell lines in vitro was evaluated in terms of cell viability, expression of HSP90 client proteins, and impact on cancer stem cells. An in vivo model with trastuzumab-resistant JIMT-1 cells was used to examine the efficacy and toxicity of HVH-2930. Results: HVH-2930 was rationally designed to fit into the ATP-binding pocket interface cavity of the hHSP90 homodimer in the C-terminal domain of HSP90, stabilizing its open conformation and hindering ATP binding. HVH-2930 induces apoptosis without inducing the HSR but by specifically suppressing the HER2 signaling pathway. This occurs with the downregulation of HER2/p95HER2 and disruption of HER2 family member heterodimerization. Attenuation of cancer stem cell (CSC)-like properties was associated with the downregulation of stemness factors such as ALDH1, CD44, Nanog and Oct4. Furthermore, HVH-2930 administration inhibited angiogenesis and tumor growth in trastuzumab-resistant xenograft mice. A synergistic effect was observed when combining HVH-2930 and paclitaxel in JIMT-1 xenografts. Conclusion: Our findings highlight the potent efficacy of HVH-2930 in overcoming trastuzumab resistance in HER2-positive breast cancer. Further investigation is warranted to fully establish its therapeutic potential.

Management of newborns and healthcare workers exposed to isoniazid-resistant congenital tuberculosis in the neonatal intensive care unit

BACKGROUND

Management of newborns and healthcare workers (HCWs) exposed to congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) has been reported rarely.

AIM

To outline a contact investigation process for individuals exposed to congenital TB in the NICU and investigate nosocomial transmission. Additionally, to assess the efficacy and safety of window prophylaxis in exposed newborns.

METHODS

A baby, born at a gestational age of 28 + 1 weeks, was diagnosed with isoniazid-resistant congenital TB on the 39th day of admission to the level IV NICU. Newborns and HCWs exposed cumulatively for ≥8 h underwent contact investigation and follow-up for a year.

FINDINGS

Eighty-two newborns underwent contact investigation. All newborns displayed normal chest X-rays, and 42 hospitalized newborns tested negative for acid-fast bacilli stain and Xpert® MTB/RIF assay in their endotracheal sputum or gastric juices. Eighty received window prophylaxis: six of 75 on rifampin experienced mild adverse events, and none of the five on levofloxacin. After 12 weeks, five (6.1%) had a positive tuberculin skin test, all of whom had already received the Bacillus Calmette-Guérin vaccine and tested negative on TB interferon-gamma releasing assay. Of 119 exposed HCWs, three (2.5%) were diagnosed with latent TB infection and completed a four-month rifampin therapy. There was no active TB disease among exposed newborns and HCWs during a one-year follow-up.

CONCLUSION

Timely diagnosis of congenital TB is crucial for minimizing transmission among exposed neonates and HCWs in the NICU setting. In cases of isoniazid-resistant index patients, even premature newborns may consider the use of rifampin or levofloxacin for window prophylaxis.

Evaluation of efficacy of Silybum marianum flower extract on the mitigating hair loss in vitro and in vivo

BACKGROUND

Natural components that can exert a wide range of anti-hair loss activity with fewer side effects are in high demand. The objective of this study was to investigate the anti-hair loss potential of Silybum marianum flower extract (SMFE) in vitro and in vivo.

METHODS

The effect of SMFE on dermal papilla cells was evaluated by measuring cell proliferation and VEGF production in hair follicle dermal papilla cells (HFDPCs). In addition, to confirm the effect of SMFE on dermal papilla senescence, SA-β-gal staining and senescence associated secretory phenotype (SASP) production such as IL-6 was observed in both replicative and hydrogen peroxide (H2 O2 )-induced senescence models. In a clinical study, hair growth was determined by reconstitution analysis after shaving the hair of the clinical subject's scalp and hair area.

RESULTS

SMFE increased the proliferation and VEGF production of HFDPCs. It also suppressed cellular senescence of HFDPCs and IL-6 production in replicative senescence and oxidative stress-induced senescence models. The hair density and total hair count at 16 and 24 weeks after using hair shampoo containing SMFE were significantly increased compared with those of the placebo group.

CONCLUSION

SMFE has the potential to be used as a natural ingredient for alleviating hair loss.

Fermented black ginseng extract prevents UVB-induced inflammation by regulating the nc886-PKR pathway in human keratinocytes

BACKGROUND

Continuous exposure of the skin to ultraviolet B (UVB) rays can cause inflammation and photodamage. In previous studies, we observed that the upregulation of nc886, a noncoding RNA (ncRNA), can alleviate UVB-induced inflammation through suppression of the protein kinase RNA (PKR) pathway. We aim to investigate the effect of fermented black ginseng extract (FBGE), which has been shown to increase the expression of nc886, on UVB-induced inflammation in keratinocytes.

METHODS

To confirm the cytotoxicity of FBGE, MTT assay was performed, and no significant cytotoxicity was found on human keratinocytes. The efficacies of FBGE were assessed through qPCR, Western blotting, and ELISA analysis which confirmed regulation of UVB-induced inflammation.

RESULTS

The analysis results showed that FBGE inhibited the decrease in nc886 expression and the increase in the methylated nc886 caused by UVB. It also prevented the UVB-induced increase of metalloproteinase-9 (MMP-9), metalloproteinase-1 (MMP-1), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α). Additionally, FBGE suppressed the PKR-MAPK pathways activated by UVB.

CONCLUSION

These results implicate that FBGE can alleviate UVB-induced inflammation through regulation of the nc886-PKR pathway.

Suppression of TNBC metastasis by doxazosin, a novel dual inhibitor of c-MET/EGFR

BACKGROUND

Triple-negative breast cancer (TNBC) is characterized by aggressive growth and a high propensity for recurrence and metastasis. Simultaneous overexpression of c-MET and EGFR in TNBC is associated with worse clinicopathological features and unfavorable outcomes. Although the development of new c-MET inhibitors and the emergence of 3rd-generation EGFR inhibitors represent promising treatment options, the high costs involved limit the accessibility of these drugs. In the present study, we sought to investigate the therapeutic potential of doxazosin (DOXA), a generic drug for benign prostate hyperplasia, in targeting TNBC.

METHODS

The effect of DOXA on TNBC cell lines in vitro was evaluated in terms of cell viability, apoptosis, c-MET/EGFR signaling pathway, molecular docking studies and impact on cancer stem cell (CSC)-like properties. An in vivo metastatic model with CSCs was used to evaluate the efficacy of DOXA.

RESULTS

DOXA exhibits notable anti-proliferative effects on TNBC cells by inducing apoptosis via caspase activation. Molecular docking studies revealed the direct interaction of DOXA with the tyrosine kinase domains of c-MET and EGFR. Consequently, DOXA disrupts important survival pathways including AKT, MEK/ERK, and JAK/STAT3, while suppressing CSC-like characteristics including CD44high/CD24low subpopulations, aldehyde dehydrogenase 1 (ALDH1) activity and formation of mammospheres. DOXA administration was found to suppress tumor growth, intra- and peri-tumoral angiogenesis and distant metastasis in an orthotopic allograft model with CSC-enriched populations. Furthermore, no toxic effects of DOXA were observed in hepatic or renal function.

CONCLUSIONS

Our findings highlight the potential of DOXA as a therapeutic option for metastatic TNBC, warranting further investigation.

The effect of Salix alba L. bark extract on dark circles in vitro and in vivo

OBJECTIVE

Dark circles in the infraorbital area are a common cosmetic concern among individuals because they exhibit fatigue and are undesirable across all ages. Of the dark circle etiologies, blood stasis by poor-vascular integrity can cause darkening of the lower eyelid skin, which might be alleviated by reduced endothelial permeability. In this study, we investigated the effects of Salix alba bark extract (SABE) on the synthesis of hyaluronic acid (HA) in fibroblasts and vascular integrity protection from inflammatory cytokine. We also performed a clinical trial investigating the effect of SABE on dark circles.

METHODS

To confirm the effect of SABE on HA synthesis in human dermal fibroblasts (HDFs), we performed ELISA and real-time PCR. We investigated the interaction HDF-secreted substance with vascular integrity, and human dermal microvascular endothelial cells (HMEC-1) were treated with conditioned medium (CM) from HDF treated with or without SABE. Subsequently, we conducted a clinical study on 29 subjects by having them apply SABE containing cream for 8 weeks.

RESULTS

Salix alba bark extract treatment increased HA synthesis and regulated HMW-HA-related gene expressions in HDF. CM from SABE-treated HDF alleviated endothelial permeability and led to improved vascular integrity in HMEC-1 cells. Treatment with the cream containing 2% SABE for 8 weeks improved the parameters measuring dark circles, skin microcirculation and elasticity.

CONCLUSION

Our results showed that SABE could protect against dark circles in vitro, and that topical treatment of SABE improved the clinical indexes of dark circles in a clinical study. Therefore, SABE can be used as an active ingredient for improving dark circles.

Albizia julibrissin Exerts Anti-Obesity Effects by Inducing the Browning of 3T3L1 White Adipocytes

This study investigated the effects of the Albizia julibrissin Leaf extracts (AJLE) on adipocytes using 3T3-L1 cells. AJLE inhibited adipogenesis by reducing the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding proteins (C/EBPs) that regulate enzymes involved in fat synthesis and storage, and subsequently reduced intracellular lipid droplets, glycerol-3-phosphate dehydrogenase (GPDH), and triglyceride (TG). AJLE also increased the expression of brown adipocyte markers, such as uncoupling protein-1 (UCP-1), PR/SET domain 16 (PRDM16), and bone morphogenetic protein 7 (BMP7) by inducing the differentiation of brown adipocytes, as shown by a decrease in the lipid droplet sizes and increasing mitochondrial mass. AJLE increased the expression of transcription factor A, mitochondrial (TFAM), mitochondrial DNA (mtDNA) copy number, and UCP-1 protein expression, all of which are key factors in regulating mitochondrial biogenesis. AJLE-induced browning was shown to be regulated by the coordination of AMPK, p38, and SIRT1 signaling pathways. The ability of AJLE to inhibit adipogenesis and induce brown adipocyte differentiation may help treat obesity and related diseases.

A dual-action niclosamide-based prodrug that targets cancer stem cells and inhibits TNBC metastasis

Chemotherapy typically destroys the tumor mass but rarely eradicates the cancer stem cells (CSCs) that can drive metastatic recurrence. A key current challenge is finding ways to eradicate CSCs and suppress their characteristics. Here, we report a prodrug, Nic-A, created by combining a carbonic anhydrase IX (CAIX) inhibitor, acetazolamide, with a signal transducer and transcriptional activator 3 (STAT3) inhibitor, niclosamide. Nic-A was designed to target triple-negative breast cancer (TNBC) CSCs and was found to inhibit both proliferating TNBC cells and CSCs via STAT3 dysregulation and suppression of CSC-like properties. Its use leads to a decrease in aldehyde dehydrogenase 1 activity, CD44high/CD24low stem-like subpopulations, and tumor spheroid-forming ability. TNBC xenograft tumors treated with Nic-A exhibited decreased angiogenesis and tumor growth, as well as decreased Ki-67 expression and increased apoptosis. In addition, distant metastases were suppressed in TNBC allografts derived from a CSC-enriched population. This study thus highlights a potential strategy for addressing CSC-based cancer recurrence.

Epigenetic regulation of SMAD3 by histone methyltransferase SMYD2 promotes lung cancer metastasis

Epigenetic alterations, especially histone methylation, are key factors in cell migration and invasion in cancer metastasis. However, in lung cancer metastasis, the mechanism by which histone methylation regulates metastasis has not been fully elucidated. Here, we found that the histone methyltransferase SMYD2 is overexpressed in lung cancer and that knockdown of SMYD2 could reduce the rates of cell migration and invasion in lung cancer cell lines via direct downregulation of SMAD3 via SMYD2-mediated epigenetic regulation. Furthermore, using an in vitro epithelial-mesenchymal transition (EMT) system with a Transwell system, we generated highly invasive H1299 (In-H1299) cell lines and observed the suppression of metastatic features by SMYD2 knockdown. Finally, two types of in vivo studies revealed that the formation of metastatic tumors by shSMYD2 was significantly suppressed. Thus, we suggest that SMYD2 is a potential metastasis regulator and that the development of SMYD2-specific inhibitors may help to increase the efficacy of lung cancer treatment.

Tcf7l2 in hepatocytes regulates de novo lipogenesis in diet-induced non-alcoholic fatty liver disease in mice

AIMS/HYPOTHESIS

Non-alcoholic fatty liver disease (NAFLD) associated with type 2 diabetes may more easily progress towards severe forms of non-alcoholic steatohepatitis (NASH) and cirrhosis. Although the Wnt effector transcription factor 7-like 2 (TCF7L2) is closely associated with type 2 diabetes risk, the role of TCF7L2 in NAFLD development remains unclear. Here, we investigated how changes in TCF7L2 expression in the liver affects hepatic lipid metabolism based on the major risk factors of NAFLD development.

METHODS

Tcf7l2 was selectively ablated in the liver of C57BL/6N mice by inducing the albumin (Alb) promoter to recombine Tcf7l2 alleles floxed at exon 5 (liver-specific Tcf7l2-knockout [KO] mice: Alb-Cre;Tcf7l2^f/f). Alb-Cre;Tcf7l2^f/f and their wild-type (Tcf7l2^f/f) littermates were fed a high-fat diet (HFD) or a high-carbohydrate diet (HCD) for 22 weeks to reproduce NAFLD/NASH. Mice were refed a standard chow diet or an HCD to stimulate de novo lipogenesis (DNL) or fed an HFD to provide exogenous fatty acids. We analysed glucose and insulin sensitivity, metabolic respiration, mRNA expression profiles, hepatic triglyceride (TG), hepatic DNL, selected hepatic metabolites, selected plasma metabolites and liver histology.

RESULTS

Alb-Cre;Tcf7l2^f/f essentially exhibited increased lipogenic genes, but there were no changes in hepatic lipid content in mice fed a normal chow diet. However, following 22 weeks of diet-induced NAFLD/NASH conditions, liver steatosis was exacerbated owing to preferential metabolism of carbohydrate over fat. Indeed, hepatic Tcf7l2 deficiency enhanced liver lipid content in a manner that was dependent on the duration and amount of exposure to carbohydrates, owing to cell-autonomous increases in hepatic DNL. Mechanistically, TCF7L2 regulated the transcriptional activity of Mlxipl (also known as ChREBP) by modulating O-GlcNAcylation and protein content of carbohydrate response element binding protein (ChREBP), and targeted Srebf1 (also called SREBP1) via miRNA (miR)-33-5p in hepatocytes. Eventually, restoring TCF7L2 expression at the physiological level in the liver of Alb-Cre;Tcf7l2^f/f mice alleviated liver steatosis without altering body composition under both acute and chronic HCD conditions.

CONCLUSIONS/INTERPRETATION

In mice, loss of hepatic Tcf7l2 contributes to liver steatosis by inducing preferential metabolism of carbohydrates via DNL activation. Therefore, TCF7L2 could be a promising regulator of the NAFLD associated with high-carbohydrate diets and diabetes since TCF7L2 deficiency may lead to development of NAFLD by promoting utilisation of excess glucose pools through activating DNL.

DATA AVAILABILITY

RNA-sequencing data have been deposited into the NCBI GEO under the accession number GSE162449 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE162449 ).

Ebastine impairs metastatic spread in triple-negative breast cancer by targeting focal adhesion kinase

We sought to investigate the utility of ebastine (EBA), a second-generation antihistamine with potent anti-metastatic properties, in the context of breast cancer stem cell (BCSC)-suppression in triple-negative breast cancer (TNBC). EBA binds to the tyrosine kinase domain of focal adhesion kinase (FAK), blocking phosphorylation at the Y397 and Y576/577 residues. FAK-mediated JAK2/STAT3 and MEK/ERK signaling was attenuated after EBA challenge in vitro and in vivo. EBA treatment induced apoptosis and a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f, suggesting that EBA targets BCSC-like cell populations while reducing tumor bulk. EBA administration significantly impeded BCSC-enriched tumor burden, angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Our findings suggest that EBA may represent an effective therapeutic for the simultaneous targeting of JAK2/STAT3 and MEK/ERK for the treatment of molecularly heterogeneous TNBC with divergent profiles. Further investigation of EBA as an anti-metastatic agent for the treatment of TNBC is warranted.

Abstract 4037: Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features

Background and Purpose: Triple-negative breast cancer (TNBC) tumors typically harbor a high cancer stem-like population leading to chemo-resistance, recurrence, and metastasis. Tumor metastasis is associated with 90% of cancer-related deaths, highlighting the urgent clinical unmet need. Doxazosin is known to inhibit cell migration and invasion in several cancer cell types; however, the precise mechanisms underlying doxazosin’s anticancer effects in TNBC have not been fully elucidated. In the present study, we sought to investigate the mechanism of action of doxazosin responsible for its effects on apoptosis, cancer stem cell (CSC)-like properties, cell migration, and metastasis in TNBC.

Experimental designs: Doxazosin on TNBC cell lines [MDA-MB-231, BT549, and 4T1] in vitro was evaluated in cell viability, apoptosis, cell migration, CD44/CD24 staining, ALDH1 activity, and mammosphere formation. The effect of doxazosin on tumor growth, angiogenesis, and metastasis was evaluated in an orthotopic allograft mice model with CSC-enriched population.

Results: Doxazosin significantly reduced cell viability and induced apoptosis in MDA-MB-231 and BT549 cells via activation of caspase-3/-7 and cleavage of PARP. Doxazosin significantly suppressed cell migratory capability, concomitant with disrupting cytoskeletal proteins, including vimentin and F-actin expression in TNBC cells. An impairment of BCSC-like properties was associated with reduction of ALDH1 activity and the CD44+/CD24- population, concomitant with suppression of mammosphere-forming ability. Doxazosin administration reduced tumor growth and lung metastasis, as evidenced by a sharp decline in bioluminescence signal intensity. Inhibitory effect of tumor growth was accompanied by a significant decrease of Ki-67 and enhancement of apoptosis with DNA fragmentation and increased cleaved-caspase-3 expression. The latter phenomenon was associated with the impediment of JAK2/STAT3 signaling pathway and CSC-like properties. Furthermore, no toxic effects of doxazosin were found in liver and kidney function in animals.

Conclusion: Taken together, our findings highlight doxazosin as a promising candidate for drug repurposing in suppressing metastatic TNBC.

Citation Format: Seongjae Kim, Dongmi Ko, Juyeon Seo, Soeun Park, Minsu Park, Kee Dal Nam, Yong koo Kang, So Ra Seock, Jaeyoun Park, Eunhye Oh, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4037.

Abstract 423: β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance

Purpose: Trastuzumab resistance is a multifactorial phenomenon arising from the steric effects of p95HER2, activation of HER2 downstream signaling pathways, and the existence of cancer stem cells. We sought to examine the capacity of β-escin, an anti-inflammatory drug, to address trastuzumab resistance in HER2-positive breast cancer cells.

Experimental designs: The effects of β-escin in trastuzumab-sensitive and -resistant cell lines were evaluated for apoptosis, HER2 expression, calpain activation and CSC-like properties. In vivo trastuzumab-resistant xenograft mice model was used to examine tumor growth, angiogenesis and organ toxicity of β-escin.

Results: β-escin induced mitochondrial-mediated apoptosis accompanied by reactive oxygen species (ROS) production and increased active p18Bax fragmentation, leading to caspase-3/-7 activation. β-escin downregulated p95HER2, HER2 and HER3 as well as their phosphorylation. β-escin-induced HER2 degradation appears to be mediated by calpain activation. We observed that treatment with β-escin induced cleavage of HER2 and p95HER2 (at 75, 50 and 42 kDa fragments) in HER2 overexpressing MDA-MB-231 cells. Attenuation of CSC-related features by β-escin challenge was accompanied by marked reductions in CD44high/CD24low stem-like cells and aldehyde dehydrogenase 1 (ALDH1) activity as well as hindrance of mammosphere formation. β-escin administration also significantly retarded tumor growth and angiogenesis in a trastuzumab-resistant JIMT-1 xenograft model via downregulation of CSC-associated markers and intracellular domain HER2. Importantly, β-escin selectively inhibited malignant cells and was less toxic to normal mammary cells, and no toxic effects were found in liver and kidney function in animals.

Conclusion: Herein, for the first time, we report the potent efficacy of β-escin, a drug repurposing candidate with an exceptional safety profile in addressing trastuzumab-resistant HER2-positive breast cancer.

Citation Format: Soeun Park, Minsu Park, Dongmi Ko, Seongjae Kim, Juyeon Seo, Kee Dal Nam, Eunsun Jung, Yong koo Kang, Seojin Jang, So Ra Seock, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo, Jaeyoun Park. β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 423.

Abstract 5805: Ebastine targets cancer stem cell-like properties and metastasis in triple-negative breast cancer by binding focal adhesion kinase

Triple-negative breast cancer (TNBC) exhibits an aggressive behavior associated with poor prognosis due to the absence of established molecular targets. Focal adhesion kinase (FAK) is a major determinant and participates in the acquisition of migration and invasion, as well as the maintenance of breast cancer stem cell (BCSC)-like traits in TNBC. We sought to investigate the effect of ebastine, a second-generation antihistamine on apoptosis, FAK activation, BCSC subpopulations and metastasis in TNBC in vitro and in vivo. TCGA dataset analysis revealed that mRNA levels of FAK were highly expressed in TNBC compared to other breast cancer subtypes. We found that ebastine binds to the tyrosine kinase domain of FAK, which blocks phosphorylation at the Y397 and Y576/577 residues and subsequent inactivation of SRC. Ebastine-induced apoptosis was associated with attenuation of JAK2/STAT3 and MEK/ERK signaling in TNBC cells. Kinetic analysis revealed a concentration-dependent impairment of cell migration in the presence of ebastine in MDA-MB-231 and 4T1 cells in vitro. Ebastine targets BCSC-like cell populations as evidenced by a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f and suppression of mammosphere-forming capacity. Ebastine administration led to a significant reduction in the growth ebastine of BCSC-enriched 4T1 mammospheres orthotopically injected into the mammary glands of Balb/c mice. Ebastine administration significantly impeded angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Importantly, biochemical analysis in mice serum showed that ebastine had no effect on liver and kidney function. Our findings suggest that EBA may be an effective therapeutic repositioning candidate for the simultaneous targeting of multiple survival signaling pathways for the treatment of molecularly heterogeneous TNBC. Further investigation of ebastine as an anti-metastatic agent for the treatment of TNBC is warranted.

Citation Format: Juyeon Seo, Minsu Park, Dongmi Ko, Seongjae Kim, Soeun Park, Kee Dal Nam, Yong Koo Kang, So Ra Seuk, Jaeyoun Park, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. Ebastine targets cancer stem cell-like properties and metastasis in triple-negative breast cancer by binding focal adhesion kinase. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5805.

Abstract 5800: Anti-metastatic potential of pitavastatin in triple-negative breast cancer via targeting breast cancer stem-like properties and STAT3 signaling

Triple-negative breast cancer (TNBC) is the most deadly and aggressive phenotype, with a higher rate of metastatic recurrence. TNBC does yet have a suitable treatment option other than cytotoxic anticancer drugs. Although pitavastatin has been shown to exert anti-proliferative effects and cytotoxicity in various types of cancer cells, the precise mechanisms underlying pitavastatin’s anti-cancer effects in TNBC have not been fully elucidated. We sought to investigate the mechanism of pitavastatin-induced apoptosis and its effects on cancer stem cell (CSC)-like characteristics in TNBC. Exposure to pitavastatin induced mitochondria-mediated apoptotic cell death in BT549 and 4T1 cells. Mitochondrial dysfunction was accompanied with a robust production of reactive oxygen species (ROS) and collapse of mitochondrial membrane potential (MMP), resulting in subsequent activation of caspase-3/-7 and PARP cleavage. Pitavastatin effectively suppressed CSC-like properties in TNBC via targeting CD44+/CD24- and CD49f+/CD24- phenotypes, as well as impediment of mammosphere formation in vitro. This phenomenon was accompanied with dysregulation of STAT3 survival pathway, concomitant with significant downregulation of cyclin D1, survivin and vimentin. Pitavastatin effectively targets both the proliferating TNBC tumor cells and CSCs via the dysregulation of STAT3 and suppression of CSC-like properties, markedly reducing angiogenesis and tumor growth, coinciding with decreased Ki-67 expression. It is noteworthy that pitavastatin considerably suppressed metastasis, coinciding with significant reduction of MMP-2, MMP-9 and VEGF in the circulating blood of mice. Our findings highlight that pitavastatin may be potentially effective for the treatment of metastatic TNBC.

Citation Format: Dongmi Ko, Juyeon Seo, Seongjae Kim, Soeun Park, Minsu Park, Kee Dal Nam, Yong koo Kang, Sora Seock, Eunsun Jung, Yoon-Jae Kim, Jaeyoun Park, Ji Young Kim, Jae Hong Seo. Anti-metastatic potential of pitavastatin in triple-negative breast cancer via targeting breast cancer stem-like properties and STAT3 signaling. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5800.

Abstract 6121: UCP2 inhibitor eradicates cancer stem-like population in trastuzumab-resistant HER2-positive breast cancer

Purpose: Uncoupling protein 2 (UCP2) is a member of the mitochondrial anion carrier protein family that plays an important role in stabilizing the inner mitochondrial membrane potential (MMP, ΔΨm) and controlling reactive oxygen species (ROS) production. A selective UCP2 inhibitor, genipin is known to elicit cytotoxicity in several cancers, however, its effects on cancer stem cells (CSCs)-like properties and trastuzumab resistance in HER2-positive breast cancer cells have not been fully elucidated. In the present study, we sought to investigate the mechanism of action of genipin responsible for the induction of apoptosis and its effects on CSC-like features, expression of HER family member and trastuzumab resistance in HER2-positive breast cancer cells in vitro and in vivo.

Experimental Designs: The effects of genipin on trastuzuamb-sensitive [BT474 and SKBR3] and trastuzumab-resistant [JIMT-1 and MDA-MB-453] HER2-positive breast cancer cell lines in vitro were evaluated for cell viability, Sub-G1, ROS, MMP, ALDH1 activity, CD44+/CD24- subpopulation and mammosphere formation. To confirm the physiological relevance of our in vitro observations, we explored the impact of genipin on tumor growth and angiogenesis and expression of p95HER2 and ALDH1A1 in trastuzumab-resistant xenograft model in vivo.

Results: HER2-positive breast cancer cells harbored a higher level of UCP2, when compared to their counterparts. Genipin significantly downregulated UCP2 and mitochondrial dysfunction coinciding with increased ROS generation and disruption of MMP. These phenomena were accompanied with upregulation of the Bax/Bcl-2 ratio and activation of caspase-3 and caspase-7. Genipin treatment led to significant reduction in levels of truncated p95HER2, p-HER2, p-HER3 and p-Akt levels in both trastuzumab-sensitive and -resistant lines. Marked decline of CD44 and ALDH1A1 expression by genipin treatment was associated with attenuation of mammosphere-forming ability. UCP2 level is predominantly upregulated in CSC-enriched populations, while its knockdown significantly suppressed CSC-like characteristics concomitant with decreased ALDH1A1 and CD44 expression as well as impairment of ALDH1 activity. Genipin administration significantly retarded tumor growth and angiogenesis in trastuzumab-resistant JIMT-1 xenograft tumors. The antitumor effect occurred concomitantly with a decrease in Ki-67 proliferating index and enhancement of apoptosis. Furthermore, individuals receiving genipin exhibited markedly lower levels of p95HER2, full-length p185HER2, CD44 and ALDH1A1 expression compared to their control counterparts.

Conclusion: To our knowledge, our findings are the first reported instance of genipin-induced suppression of CSC-like properties and HER2/HER3/Akt axis, implying that genipin treatment may have application in addressing trastuzumab resistance.

Citation Format: Minsu Park, Soeun Park, Juyeon Seo, Dongmi Ko, Seongjae Kim, Yong Koo Kang, Kee Dal Nam, So Ra Seuk, Tae-Min Cho, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. UCP2 inhibitor eradicates cancer stem-like population in trastuzumab-resistant HER2-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6121.

Assessment of the anti-hair loss potential of Camellia japonica fruit shell extract in vitro

OBJECTIVE

Hair loss is caused by various factors. Impacts of these factors are often overlapped and intensified. Currently, mitigation of hair loss is being studied by proliferating dermal papilla cells (DPCs) and inhibiting deleterious factors such as dihydrotestosterone (DHT) and oxidative stress on hair growth. Camellia japonica (C. japonica) fruit shell is a discarded part. Its biological activity remains to be elucidated. In this study, we investigated the capacity of C. japonica fruit shell extract (CJFSE) for hair loss mitigation.

METHODS

MTT assay, spheroid culture and quantitative RT-PCR were performed to observe the proliferative effect of CJFSE on hair follicle dermal papilla cells (HFDPCs). Effects of CJFSE on DHT-induced hair loss were confirmed by Dkk-1 ELISA, β-galactosidase (β-gal) and 5α-reductase activity assay. In addition, effects of CJFSE on oxidative stress were confirmed through DPPH and ROS production assays.

RESULTS

CJFSE increased the proliferation and spheroid size of HFDPCs. Expression levels of VEGF-A, Wnt-1, c-Myc and Cyclin D1 were upregulated by CJFSE. CJFSE also suppressed 5α-reductase activity and DHT-induced decrease in cell proliferation, Dkk-1 secretion and β-gal activity. Moreover, CJFSE showed DPPH scavenging activity and ameliorated hydrogen peroxide-induced ROS production and β-gal activity. Finally, gallic acid and protocatechuic acid were observed in CJFSE through HPLC analysis.

CONCLUSION

CJFSE has the potential to alleviate hair loss by promoting hair cell growth and suppressing effects of DHT and oxidative stress on hair.

β-Escin overcomes trastuzumab resistance in HER2-positive breast cancer by targeting cancer stem-like features

Background

The emergence of de novo or intrinsic trastuzumab resistance is exceedingly high in breast cancer that is HER2 positive and correlates with an abundant cancer stem cell (CSC)-like population. We sought to examine the capacity of β-escin, an anti-inflammatory drug, to address trastuzumab resistance in HER2-positive breast cancer cells.

Methods

The effect of β-escin on trastuzumab-resistant and -sensitive cell lines in vitro was evaluated for apoptosis, expression of HER2 family members, and impact on CSC-like properties. An in vivo model of trastuzumab-resistant JIMT-1 was used to examine the efficacy and toxicity of β-escin.

Results

β-escin induced mitochondrial-mediated apoptosis accompanied by reactive oxygen species (ROS) production and increased active p18Bax fragmentation, leading to caspase-3/-7 activation. Attenuation of CSC-related features by β-escin challenge was accompanied by marked reductions in CD44^high/CD24^low stem-like cells and aldehyde dehydrogenase 1 (ALDH1) activity as well as hindrance of mammosphere formation. β-escin administration also significantly retarded tumor growth and angiogenesis in a trastuzumab-resistant JIMT-1 xenograft model via downregulation of CSC-associated markers and intracellular domain HER2. Importantly, β-escin selectively inhibited malignant cells and was less toxic to normal mammary cells, and no toxic effects were found in liver and kidney function in animals.

Conclusions

Taken together, our findings highlight β-escin as a promising candidate for the treatment of trastuzumab-resistant HER2-positive breast cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02713-9.

Immune-enhancing effect of water-soluble beta-glucan derived from enzymatic hydrolysis of yeast glucan

Immunostimulants play an important role in the treatment of immunodeficiency. Macrophages are the first line in our immune defense system and play a critical role in the immune response. Therefore, finding new and better substances to induce an immune response by activating macrophages is an attractive research topic, especially in the fields of immunopharmacology and cancer prevention. Keratinocytes actively crosstalk with immune cells during wound repair, so enhancing the function of keratinocytes is also an important part of improving immunity. Beta-glucans are naturally occurring polysaccharides, consisting of d-glucose monomers linked by beta-glycosidic bonds. Several studies have investigated the immunomodulatory effects of beta-glucan, such as its anti-inflammatory and antibacterial properties. However, the use of yeast cell wall glucan has been limited because it is not soluble in water. In this study, we produced low-molecular-weight water-soluble yeast glucan (WSY glucan) and confirmed various aspects of its immune-enhancing effect. The structure of the beta-(1→3) and (1→6) bonds of WSY glucan were confirmed by nuclear magnetic resonance spectroscopy (¹H-NMR) analysis. Our results showed that treatment with WSY glucan significantly and dose-dependently induced the production of inflammatory mediators (prostaglandin E₂ (PGE₂) and nitric oxide (NO)) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-6) in macrophages. In addition, WSY glucan treatment showed changes in the morphological structure of the macrophages and promoted phagocytic activity of the macrophages and wound healing in keratinocytes. Based on these results, WSY glucan is considered as a potential candidate for the treatment of diseases related to the weakening of the immune system without the limitation of insolubility.

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Soluble low-molecular-weight beta-glucan, WSY-glucan, was produced through enzymatic hydrolysis.

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WSY glucan significantly and dose-dependently induced the production of pro-inflammatory cytokines (TNF-α and IL-6) and inflammatory mediators (NO and prostaglandin E₂) in macrophages.

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WSY glucan treatment showed changes in the morphological structure of the macrophages and promoted phagocytic activity of the macrophages and wound healing in keratinocytes.

Isatis tinctoria L. Leaf Extract Inhibits Replicative Senescence in Dermal Fibroblasts by Regulating mTOR-NF-κB-SASP Signaling

Senescent fibroblasts progressively deteriorate the functional properties of skin tissue. Senescent cells secrete senescence-associated secretory phenotype (SASP) factor, which causes the aging of surrounding non-senescent cells and accelerates aging in the individuals. Recent findings suggested the senomorphic targeting of the SASP regulation as a new generation of effective therapeutics. We investigated whether Isatis tinctoria L. leaf extract (ITE) inhibited senescence biomarkers p53, p21^CDKN1A, and p16^INK4A gene expression, and SASP secretions by inhibiting cellular senescence in the replicative senescent human dermal fibroblast (RS-HDF). ITE has been demonstrated to inhibit the secretion of SASP factors in several senomorphic types by regulating the MAPK/NF-κB pathway via its inhibitory effect on mTOR. ITE suppressed the inflammatory response by inhibiting mTOR, MAPK, and IκBα phosphorylation, and blocking the nuclear translocation of NF-κB. In addition, we observed that autophagy pathway was related to inhibitory effect of ITE on cellular senescence. From these results, we concluded that ITE can prevent and restore senescence by blocking the activation and secretion of senescence-related factors generated from RS-HDFs through mTOR-NF-κB regulation.

Effect of Cirsium japonicum Flower Extract on Skin Aging Induced by Glycation

Advanced glycation end products (AGEs) have recently been increasingly discussed as one factor of skin aging. In this study, we investigated the effects of Cirsium japonicum flower (CFE) extract on glycation in relation to skin aging and skin elasticity. Moreover, we learned the main active constituent of CFE that has effects against glycation. To demonstrate the effects of CFE on glycation, we carried out an in vitro glycation study, 3-dimensional culture, and clinical study. As a result, CFE inhibited formation of AGEs in both bovine serum albumin (BSA)/glucose glycation system and aldehyde-derived glycation system. Moreover, CFE reduced Nε-(carboxymethyl), lysine (CML), and carbonylated proteins that increased by glycation. Furthermore, CFE broke crosslinks of collagen–AGEs and inhibited the increase of matrix metalloproteinase-1 (MMP-1) gene expression by AGEs. In the 3D culture condition, CFE restored the reduction of collagen gel contraction by glycation. Moreover, apigenin was detected as the main active constituent in CFE that has anti-glycation effects. In the clinical study, we confirmed that CFE has effects on skin wrinkles and skin elasticity. Our findings suggest that CFE can be used as a cosmetic or cosmeceutical ingredient for improving skin elasticity and wrinkles. Regulation of AGEs can be an interesting target for anti-aging.

Chlorogenic Acid Isomers Isolated from Artemisia lavandulaefolia Exhibit Anti-Rosacea Effects In Vitro

Rosacea is a chronic inflammatory disease affecting facial skin. It is associated with immune and vascular dysfunction mediated via increased expression and activity of cathelicidin and kallikrein 5 (KLK5), a serine protease of stratum corneum. Therefore, KLK5 inhibitors are considered as therapeutic agents for improving the underlying pathophysiology and clinical manifestation of rosacea. Here, we isolated the active constituents of Artemisia lavandulaefolia (A. lavandulaefolia) and investigated their inhibitory effect on KLK5 protease activity. Using bioassay-guided isolation, two bioactive compounds including chlorogenic acid isomers, 3,5-dicaffeoylquinic acid (isochlorogenic acid A) (1), and 4,5-dicaffeoylquinic acid (isochlorogenic acid C) (2) were isolated from A. lavandulaefolia. In this study, we evaluated the effects of isochlorogenic acids A and C on dysregulation of vascular and immune responses to rosacea, and elucidated their molecular mechanisms of action. The two chlorogenic acid isomers inhibit KLK5 protease activity, leading to reduced conversion of inactive cathelicidin into active LL-37. This inhibition of LL-37 production by isochlorogenic acids A and C reveals the efficacy of suppressing the expression of inflammatory mediators induced by LL-37 in immune cells such as macrophages and mast cells. In addition, both isomers of chlorogenic acid directly inhibited the proliferation and migration of vascular endothelial cells induced by LL-37.

nc886, a Non-Coding RNA, Is a New Biomarker and Epigenetic Mediator of Cellular Senescence in Fibroblasts

Functional studies of organisms and human models have revealed that epigenetic changes can significantly impact the process of aging. Non-coding RNA (ncRNA), one of epigenetic regulators, plays an important role in modifying the expression of mRNAs and their proteins. It can mediate the phenotype of cells. It has been reported that nc886 (=vtRNA2-1 or pre-miR-886), a long ncRNA, can suppress tumor formation and photo-damages of keratinocytes caused by UVB. The aim of this study was to determine the role of nc886 in replicative senescence of fibroblasts and determine whether substances capable of controlling nc886 expression could regulate cellular senescence. In replicative senescence fibroblasts, nc886 expression was decreased while methylated nc886 was increased. There were changes of senescence biomarkers including SA-β-gal activity and expression of p16INK4A and p21Waf1/Cip1 in senescent cells. These findings indicate that the decrease of nc886 associated with aging is related to cellular senescence of fibroblasts and that increasing nc886 expression has potential to suppress cellular senescence. AbsoluTea Concentrate 2.0 (ATC) increased nc886 expression and ameliorated cellular senescence of fibroblasts by inhibiting age-related biomarkers. These results indicate that nc886 has potential as a new target for anti-aging and that ATC can be a potent epigenetic anti-aging ingredient.

Senotherapeutic-like effect of Silybum marianum flower extract revealed on human skin cells

Cellular senescence causes irreversible growth arrest of cells. Prolonged accumulation of senescent cells in tissues leads to increased detrimental effects due to senescence associated secretory phenotype (SASP). Recent findings suggest that elimination of senescent cells has a beneficial effect on organismal aging and lifespan. In this study, using a validated replicative senescent human dermal fibroblasts (HDFs) model, we showed that elimination of senescent cells is possible through the activation of an apoptotic mechanism. We have shown in this replicative senescence model, that cell senescence is associated with DNA damage and cell cycle arrest (p21, p53 markers). We have shown that Silybum marianum flower extract (SMFE) is a safe and selective senolytic agent targeting only senescent cells. The elimination of the cells is induced through the activation of apoptotic pathway confirmed by annexin V/propidium iodide and caspase-3/PARP staining. Moreover, SMFE suppresses the expression of SASP factors such as IL-6 and MMP-1 in senescent HDFs. In a co-culture model of senescent and young fibroblasts, we demonstrated that senescent cells impaired the proliferative capacities of young cells. Interestingly, when the co-culture is treated with SMFE, the cell proliferation rate of young cells is increased due to the decrease of the senescent burden. Moreover, we demonstrated in vitro that senescent fibroblasts trigger senescent process in normal keratinocytes through a paracrine effect. Indeed, the conditioned medium of senescent HDFs treated with SMFE reduced the level of senescence-associated beta-galactosidase (SA-β-Gal), p16INK4A and SASP factors in keratinocytes compared with CM of senescent HDFs. These results indicate that SMFE can prevent premature aging due to senescence and even reprograms aged skin. Indeed, thanks to its senolytic and senomorphic properties SMFE is a candidate for anti-senescence strategies.

Evaluating the Sun Protection Factor of Cosmetic Formulations Containing Afzelin

Exposure to UV radiation damages the skin and increases the risk of skin cancer. Sunscreen is used to protect the skin from the harmful effects of UV radiation. However, the chemical UV filters used in sunscreen can show toxicity and cause allergic reactions. A safe sunscreen that includes a lower content of chemical UV filters and exerts an excellent effect on UV protection needs to be developed. The objective of this study was to investigate whether the addition of afzelin to sunscreen could improve the sun protection factor (SPF). A synergistic effect between afzelin and organic sunscreen agents including padimate O and oxybenzone was confirmed. Interestingly, 100% in vitro SPF-boosting was observed when afzelin (0.05%) was applied with a standard SPF formulation containing organic sunscreens while afzelin alone had no contribution to the SPF. In vivo SPF analysis of the standard SPF formulation showed an SPF value of 13.3 that increased to 20.1 when supplemented with afzelin (0.05%). Additionally, afzelin showed no skin irritation in a human trial. These results suggest that afzelin is useful as a natural additive in sunscreen formulations and provides an SPF-boosting effect. Afzelin supplementation to the formulation showed the potential to reduce the use of synthetic photoprotectors, which could minimize the risk of synthetic agent toxicity.

Melanogenesis-promoting effect of Cirsium japonicum flower extract in vitro and ex vivo

OBJECTIVE

In this study, we examined the effect of C. japonicum flower extract (CFE) on melanogenesis and its mechanism in vitro and ex vivo.

METHODS

The effect of CFE on melanogenesis was investigated with lightly (HEMn-LP) and moderately (HEMn-MP) pigmented normal human melanocytes, reconstituted three-dimensional skin (3D skin) model and ex vivo human hair follicles. The melanogenesis-inducing effect of CFE was evaluated using melanin content and intracellular tyrosinase activity assay. The amount and type of eumelanin and pheomelanin were analysed by using HPLC method. The mechanism involved in the effect of CFE on hyperpigmentation was explored by cyclic adenosine monophosphate (cAMP) immunoassay and western blot analysis for tyrosinase, microphthalmia-associated transcription factor (MITF) and phosphorylated CRE-binding protein (pCREB) expression. The degree of pigmentation in 3D skin and L-values were measured using a CR-300 chroma meter. The amount of dissolved melanin was measured using a spectrophotometer. The content of melanin in the hair follicles was evaluated by Fontana Masson staining.

RESULTS

C. japonicum flower extract significantly increased the melanin content and cellular tyrosinase activity in both HEMn-LP and HEMn-MP cells. The markers of pheomelanin and eumelanin in HEMn-LP and HEMn-MP were also increased by CFE. We observed that CFE treatment on melanocytes increased intracellular cAMP with inducing pCREB and up-regulating the protein levels of TYR and MITF. Furthermore, CFE considerably increased the melanin content in a 3D skin model and ex vivo human hair follicles.

CONCLUSIONS

These results suggest that CFE exerts hyperpigmentation activity through cAMP signalling in human melanocytes that it can improve follicular depigmentation and vitiligo by stimulating the melanin synthesis.

P13.12 Effect of tumor treating fields on tumor microtubes in glioma

BACKGROUND

Tumor microtubes (TMs) are ultralong membrane protrusions of tumor cells in astrocytic gliomas, including glioblastomas. TMs are used as routes for brain invasion and for cells to interconnect over long distances resulting in a functional network that allows multicellular communication. This network mediates resistance against the cytotoxicity of radiation and chemotherapy. One explanation for TM network protection is a better homeostasis of calcium ions that would otherwise increase to toxic intracellular levels in response to these therapies.

Our working hypothesis is that interfering with the integrity of the glioblastoma cell network is key to a potential breakthrough in glioma therapy. Many cellular structures are polarized and composed of charged elements and are thus potential subjects to electrical forces; this might also influence the complex intercellular calcium waves (ICWs) that are characteristic for glioma networks. We were therefore interested in the effect of TTF on glioma network maintenance.

MATERIAL AND METHODS

To examine the effect of TTF on glioma TMs we have established a 2D in vitro glioma model using glioblastoma stem cells (GBSCs) grown in high-glucose medium and a 3D model using glioma tumor organoids. Both models reliably reproduce functionality and complexity of morphological features we observe in our mouse model. We analyzed the disruption of tumor network complexity and disruption of functionality by measuring intercellular calcium waves. Tumor cell death and proliferation was investigated in the 2D in vitro glioma model using the inovitroTM-System.

RESULTS

A peculiar “cricked-TM” phenotype that rarely (0.2% ±0.14) occurred under standard or control conditions was observed in TTF-treated cells (16.22% ±5.12). Cell number was reduced by 75% in two lines of GBSCs after 5 days of TTF exposure; predominantly TM-rich GBSCs (> 4 TMs) were affected. This reduction in tumor cell number corresponded with an increase in cell death (0.3% ±0.09 in untreated cells; 1.4% ±0.45 at day 5 of TTF exposure). The frequency of intercellular calcium transients, a measurement for calcium wave frequency in the glioma networks, was instantly reduced after TTF exposure to 58% ±20.42 of control levels in the primary GBSC 2D culture, and to 57.78% ±12.34 in tumor organoids derived from 3 glioblastoma patients.

CONCLUSION

This data suggests a potential effect of TTF application on tumor cell networks, at least in vitro. Interestingly, particularly those glioblastoma cells that have so far been proven to be resistant to radio- and chemotherapy appeared to be affected. We will confirm the observed effects of TTFs on tumor cell calcium signaling in our in vivo chronic cranial window mouse model. We anticipate that the results of our project will provide important insights into the underlying mechanism of TTF therapy.

P10.02 Combined methods of a micropump system and a chronic cranial window allows tumor observation with multi photon laser scanning microscopy under continuous treatment

BACKGROUND

Glioblastomas are notoriously therapy resistant tumors. As opposed to other tumor entities, no major advances in therapeutic success have been made in the past decades. This has been calling for a deeper biological understanding of the tumor, its growth and resistance patterns. We have been using a xenograft glioma model, where human glioblastoma cells are implanted under chronic cranial windows and studied longitudinally over many weeks and months using multi photon laser scanning microscopy (MPLSM). To test the effect of (new) drugs, a stable and direct delivery system avoiding the blood-brain-barrier has come into our interest.

MATERIAL AND METHODS

We implanted cranial windows and fluorescently labeled human glioblastoma stem-like cells into NMRI nude mice to follow up on the tumor development in our MPLSM model. After tumor establishment, an Alzet® micropump was implanted to directly deliver agents via a catheter system continuously over 28 days directly under the cranial window onto the brain surface. Using the MPLSM technique, the continuous delivery and infusion of drugs onto the brain and into the tumor was measured over many weeks in detail using MPLSM.

RESULTS

The establishment of the combined methods allowed reliable concurrent drug delivery over 28 days bypassing the blood-brain-barrier. Individual regions and tumor cells could be measured and followed up before, and after the beginning of the treatment, as well as after the end of the pump activity. Fluorescently labelled drugs were detectable in the MPLSM and its distribution into the brain parenchyma could be quantified. After the end of the micropump activity, further MPLSM measurements offer the possibility to observe long term effects of the applied drug on the tumor.

CONCLUSION

The combination of tumor observation in the MPSLM and concurrent continuous drug delivery is a feasible and reliable method for the investigation of (novel) anti-tumor agents, especially drugs that are not blood-brain-barrier penetrant. Morphological or even functional changes of individual tumor cells can be measured under and after treatment. These techniques can be used to test new drugs targeting the tumor, its tumor microtubes and tumor cells networks, and measure the effects longitudinally.

Anti-glycation activities of methyl gallate in vitro and in human explants

BACKGROUND

The build-up of advanced glycation end products (AGEs) is one of important factor of skin aging. Natural compounds with anti-glycation activities might have great anti-aging potential.

AIMS

The objective of this study was to evaluate an anti-glycation effects of methyl gallate as a potent ingredient for anti-aging.

METHODS

We first evaluated the AGEs inhibitory ability of methyl gallate in BSA/glucose system. Levels of Nε-CML and carbonyl contents were also measured in BSA/glucose system. To further investigate if methyl gallate could prevent glycation in full-thickness human skin explants. Glycation action was determined by the observation of the general morphology of dermis and epidermis structures and FBN-1 and of CML immunostaining. In an in-vivo study, primary irritation test was also performed to ensure the safety of methyl gallate for human skin.

RESULTS

It is known that methyl gallate can suppress glycation reaction between BSA and glucose. Methyl gallate also has a remarkable potential to reduce the oxidation of proteins. Furthermore, the anti-glycation activity of methyl gallate has been confirmed in a human skin ex-vivo model. Methyl gallate decreased the expression of CML but stimulated the expression of FBN-1 compared with MGO treatment. In an in-vivo study, methyl gallate (0.1%) did not cause any skin irritation, suggesting that methyl gallate could be used as an active ingredient in cosmetics.

CONCLUSION

Our results showed that methyl gallate could protect against glucose-mediated glycation in vitro. Furthermore, methyl gallate significantly prevented glycation in living human skin explants. Due to these beneficial effects, methyl gallate can be used to prevent or manage AGE-mediated skin aging.

Isookanin Inhibits PGE2-Mediated Angiogenesis by Inducing Cell Arrest through Inhibiting the Phosphorylation of ERK1/2 and CREB in HMEC-1 Cells

Inflammation is increasingly recognized as a critical mediator of angiogenesis, and unregulated angiogenic responses often involve human diseases. The importance of regulating angiogenesis in inflammatory diseases has been demonstrated through some successful cases of anti-angiogenesis therapies in related diseases, including arthritis, but it has been reported that some synthetic types of antiangiogenic drugs have potential side effects. In recent years, the importance of finding alternative strategies for regulating angiogenesis has begun to attract the attention of researchers. Therefore, identification of natural ingredients used to prevent or treat angiogenesis-related diseases will play a greater role. Isookanin is a phenolic flavonoid presented in Bidens extract, and it has been reported that isookanin possesses some biological properties, including antioxidative and anti-inflammatory effects, anti-diabetic properties, and an ability to inhibit α-amylase. However, its antiangiogenic effects and mechanism thereof have not been studied yet. In this study, our results indicate that isookanin has an effective inhibitory effect on the angiogenic properties of microvascular endothelial cells. Isookanin shows inhibitory effects in multiple stages of PGE₂-induced angiogenesis, including the growth, proliferation, migration, and tube formation of microvascular endothelial cells. In addition, isookanin induces cell cycle arrest in S phase, which is also the reason for subsequent inhibition of cell proliferation. The mechanism of inhibiting angiogenesis by isookanin is related to the inhibition of PGE₂-mediated ERK1/2 and CREB phosphorylation. These findings make isookanin a potential candidate for the treatment of angiogenesis-related diseases.

Anti-Inflammatory Activity and Mechanism of Isookanin, Isolated by Bioassay-Guided Fractionation from Bidens pilosa L

Bidens pilosa L. (Asteraceae) has been used historically in traditional Asian medicine and is known to have a variety of biological effects. However, the specific active compounds responsible for the individual pharmacological effects of Bidens pilosa L. (B. pilosa) extract have not yet been made clear. This study aimed to investigate the anti-inflammatory phytochemicals obtained from B. pilosa. We isolated a flavonoids-type phytochemical, isookanin, from B. pilosa through bioassay-guided fractionation based on its capacity to inhibit inflammation. Some of isookanin’s biological properties have been reported; however, the anti-inflammatory mechanism of isookanin has not yet been studied. In the present study, we evaluated the anti-inflammatory activities of isookanin using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We have shown that isookanin reduces the production of proinflammatory mediators (nitric oxide, prostaglandin E₂) by inhibiting the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated macrophages. Isookanin also inhibited the expression of activator protein 1 (AP-1) and downregulated the LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-jun NH₂-terminal kinase (JNK) in the MAPK signaling pathway. Additionally, isookanin inhibited proinflammatory cytokines (tumor necrosis factor-a (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β)) in LPS-induced THP-1 cells. These results demonstrate that isookanin could be a potential therapeutic candidate for inflammatory disease.

Rhus semialata M. extract ameliorate para-phenylenediamine-induced toxicity in keratinocytes

para-Phenylediamine (PPD), a major component of hair dyeing ingredients, can induce allergenic sensitization and exert mutagenic, tumorigenic and cytotoxic effect. In this study, we determined the cytotoxic effect of PPD on human keratinocytes and evaluated the protective effect of Rhus semialata M. extracts (RSE) on PPD induced cytotoxicity for the first time. We observed that RSE is a strong inhibitory agent against PPD-induced toxicity in human keratinocytes. The results indicated that RSE pretreatment significantly could suppress PPD induced cytotoxic effects, including decrease of cell viability, accumulation in subG1 phase of cells, and relocation of phosphatidylserine on keratinocytes. Also, we found that PPD caused cytotoxicity was associated with mitochondrial membrane potential loss and subsequent activation of caspase and PARP degradation. However, pretreatment of RSE showed preventive activities against PPD induced mitochondrial membrane potential loss and ROS production in keratinocytes. In conclusion, the results of present study suggest that RSE was able to protect the skin from several cytotoxic effects of PPD and could be a meaningful material in many industries using PPD.

Inhibition of UVB-Induced Inflammation by Laminaria japonica Extract via Regulation of nc886-PKR Pathway

Continuous exposure to ultraviolet B (UVB) can cause photodamage of the skin. This photodamage can be inhibited by the overexpression of the non-coding RNA, nc886, via the protein kinase RNA-activated (PKR) pathway. The study aims to identify how UVB inhibits nc886 expression, and it also seeks to determine whether substances that can control nc886 expression can influence UV-induced inflammation, and the mechanisms involved. The results suggest that UVB irradiation accelerates the methylation of the nc886 gene, therefore, reducing its expression. This induces the activation of the PKR, which accelerates the expression of metalloproteinase-9 (MMP-9) and cyclooxygenase (COX-2), and the production of MMP-9, prostaglandin-endoperoxide synthase (PGE2), and certain pro-inflammatory cytokines, specifically interleukin-8 (IL-8), and tumor necrosis factor- (TNF-). Conversely, in a model of nc886 overexpression, the expression and production of those inflammatory factors are inhibited. In addition, Laminaria japonica extract (LJE) protect the levels of nc886 against UVB irradiation then subsequently inhibit the production of UV-induced inflammatory factors through the PKR pathway.

MicroRNA-1258 Inhibits the Proliferation and Migration of Human Colorectal Cancer Cells through Suppressing CKS1B Expression

Increasing evidence has demonstrated that increased expression of cyclin-dependent kinase regulatory subunit 1B (CKS1B) is associated with the pathogenesis of many human cancers, including colorectal cancer (CRC). However, the regulatory mechanisms underlying the expression of CKS1B in CRC are not completely understood. Here, we investigate the role played by microRNAs in the expression of CKS1B and carcinogenesis in CRC. Among the six microRNAs predicted to target CKS1B gene expression, only miR-1258 was revealed to downregulate CKS1B expression through binding to its 3’-UTR region, as ectopic miR-1258 expression suppressed CKS1B expression and vice versa. In CRC, miR-1258 expression also decreased cell proliferation and migration in vitro and tumor growth in vivo, similar to cells with silenced CKS1B expression. Considering the highly increased levels of CKS1B and decreased expression of miR-1258 in tumors from CRC patients, these findings suggest that miR-1258 may play tumor-suppressive roles by targeting CKS1B expression in CRC. However, the therapeutic significance of these findings should be evaluated in clinical settings.

Sleep problems in Korean children with Down syndrome and parental quality of life

BACKGROUND

Sleep problems are common among children with Down syndrome (DS), and they can have a serious impact on children with DS as well as their parents and other family members. Specific aims of this study were to evaluate parent-reported sleep problems in children with DS and to examine the relationship between the sleep behaviour of children with DS and their parents' quality of life (QOL).

METHOD

A cross-sectional survey was conducted in September and October of 2017. Parents of children with DS were recruited from an online self-support community for parents of children with DS in South Korea. The mean age of the parents and children with DS was 40.40 years (SD = 5.09) and 7.89 years (SD = 3.03), respectively. Children's sleep problems and parents' QOL were assessed using the Children's Sleep Habits Questionnaire and the abbreviated version of the World Health Organization Quality of Life scale, respectively.

RESULTS

Results revealed that 83% of the parents reported that their child with DS experienced sleep problems. Children with DS had significantly more bedtime resistance, night waking, parasomnias and sleep-disordered breathing than did typically developing children. In addition, their Children's Sleep Habits Questionnaire scores were higher than those of typically developing children. Moreover, being older, being male and having more severe developmental delays were significant risk factors for sleep problems among children with DS. Furthermore, sleep problems in children with DS negatively affected parents' QOL.

CONCLUSIONS

Sleep problems negatively affect children with DS as well as their parents; therefore, health care providers should be aware of these issues and help parents manage sleep problems proactively.

P11.29 Development of ex vivo models for deeper insights into the biology and therapeutic targeting of tumor microtube networks in gliomas

BACKGROUND

The formation of multicellular networks via thin cellular protrusions named tumor microtubes (TMs) emerged as a novel mechanism of therapy resistance in malignant glioma. TMs are also involved in tumor cell invasion and growth. Within these tumor cell networks, connected tumor cells communicate via intercellular calcium waves (ICWs). Only few molecular drivers of TMs (Gap43, Ttyh1, Connexin 43) have been identified until now. Furthermore, the molecular mechanisms underlying ICWs as well as their specific biological role in glioma remains to be elucidated. A better understanding of the biology and the identification of molecular key drivers is essential for the development of drugs targeting TM formation and function.

MATERIAL AND METHODS

For this purpose, we have developed novel ex vivo models that not only provide insights into TM biology but further allow medium throughput drug screening. As classical response parameters such as the inhibition of cell growth or cytotoxicity do not necessarily correlate with effects on TM formation or function, a morphometrical approach employing laser scanning microscopy and machine-learning based image analysis tools is used. The application of fluorescent probes and genetic fluorescent reporter systems provides novel longitudinal insights into cytoskeletal dynamics, the role and exchange of organelles such as mitochondria, mechanisms of homeostasis within tumor cell networks (e.g. redox homeostasis) and ICWs in live cells. In addition to 2D glioma cell and co-culture models we have developed a fully human and mature brain organoid model. Here, complex 3D tumor cell networks corresponding to the morphology and exhibiting calcium communication patterns observed in our mouse model can be established and studied ex vivo. Furthermore, with these models not only the role of the brain microenvironment on TM formation but also direct interactions of glioma cells with neurons and glial cells as well as drug effects such as cytotoxicity on these brain cells can be investigated ex vivo.

CONCLUSION

In summary, novel tumor models enable further insights into TM biology and hence provide the basis for development of TM- and network disrupting drugs. First results of this screening opportunity will be presented.

Protective effects of Camellia japonica flower extract against urban air pollutants

Background

Exposure of skin to urban air pollutants is closely related to skin aging and inflammatory responses such as wrinkles formation, pigmentation spot, atopic dermatitis, and acne. Thus, a great deal of interest has been focused on the development of natural resources that can provide a protective effect to skin from pollutants.

Methods

The antioxidative activity of Camellia japonica flower extract (CJFE) was evaluated by 1,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay, and the inhibitory effect of CJFE by urban air pollutants-induced reactive oxygen species (ROS) production was determined in cultured normal human dermal fibroblasts (NHDFs). We additionally investigated the protective effects of CJFE against urban air pollutant using in vitro and ex vivo model.

Results

CJFE with high phenolic concentration showed antioxidative activity on scavenging capacity of 1,2-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation in a concentration dependent manner. CJFE inhibited urban air pollutants-induced ROS generation, matrixmetalloproteinase-1 (MMP-1) production and a xenobiotic response element (XRE)-luciferase activity indicating the aryl hydrocarbon receptor (AhR) transactivation. In addition, CJFE showed an excellent protective activity against pollutants-induced deteriorating effect in ex vivo model. CJFE reduced the level of pollutants-induced malondialdehyde (MDA), lipid peroxidation marker, inhibited MMP-1 expression and increased collagen synthesis. It also reduced the cell numbers with pyknotic nuclei (mainly occurring in apoptosis) and detachment of dermo-epidermal junction (DEJ) induced by pollutants.

Conclusions

Apparently, it is proposed that CJFE can be used as a protective material against pollutant-induced skin damages.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2405-4) contains supplementary material, which is available to authorized users.

nc886, a non-coding RNA, inhibits UVB-induced MMP-9 and COX-2 expression via the PKR pathway in human keratinocytes

nc886, a long non-coding RNA (ncRNA) of 101 nucleotides in length, is known as a vault RNA or microRNA precursor. Despite the recent discovery that ncRNAs in the nucleus play a crucial role in regulating chromosomal transformation and transcription, only a few studies have focused on the function of ncRNAs in the cytoplasm, such as nc886. Several studies have investigated the function of nc886 as a suppressor of carcinogenesis and inflammation in different cancer cell types; however, its role in the skin has yet to be clearly elucidated. The two RNA binding sites for protein kinase RNA-activated (PKR) are located in the central region of the stable structure of nc886, which competes with other double-stranded RNA species. Successful binding results in decreased PKR activity. Among changes in skin cells induced by ultraviolet B (UVB) radiation, nc886 expression decreases, whereas PKR phosphorylation via mitogen-activated protein kinases (MAPKs) increases. Reduced nc886 expression leads to uncontrolled PKR activity and increases in the expression of inflammatory cytokines, matrix metalloproteinase-9 (MMP-9), type IV collagenase, and cyclooxygenase (COX-2), which ultimately accelerate inflammatory responses and skin aging. The present study investigated the regulatory mechanism associated with PKR activity and nc886-PKR binding in skin cell aging and inflammation. These results suggest a role for nc886 in controlling photoaging and inflammation in skin cells.

Cks1 regulates human hepatocellular carcinoma cell progression through osteopontin expression

Precise cell cycle regulation is critical to prevent aberrant cell proliferation and cancer progression. Cks1 was reported to be an essential accessory factor for SCF^Skp2, the ubiquitin ligase that targets p27^Kip1 for proteasomal degradation; these actions drive mammalian cell transition from G1 to S phase. In this study, we investigated the role played by Cks1 in the growth and progression of human hepatocellular carcinoma (HCC) cells. Silencing Cks1 expression abrogated osteopontin (OPN) expression in a p27^Kip1-dependent manner in Huh7 HCC cells. OPN increased the proliferation, migration and invasion of Huh7 cells. Pharmacological inhibitor studies demonstrated that ERK1/2 signaling is responsible mainly for Cks1-mediated OPN expression. Cks1 appears to regulate ERK1/2 signaling through the expression of dual-specificity phosphatase 16 (DUSP16) because both Cks1 knockdown, which leads to DUSP16 upregulation, and DUSP16 overexpression decreased ERK1/2 phosphorylation and the resulting OPN expression. The same is true for the Cks1-mediated increases in p27^Kip1, suggesting that Cks1 regulates OPN expression through activating ERK1/2 signaling either by suppressing DUSP16 expression or by a p27^Kip1-dependent mechanism. Cks1 and OPN expression levels were significantly higher, but DUSP16 expression levels were significantly lower in HCC tissues than in normal liver tissues. Both Cks1 and OPN expression were negatively correlated with DUSP16 expression, whereas Cks1 expression was positively correlated with OPN expression. Moreover, combined panels for the expression levels of Cks1, DUSP16 and OPN showed significant prognostic power for the risk assessment of HCC patient overall survival. In conclusion, our data propose a novel function for Cks1 as a tumor promoter through the expression of the strongly oncogenic protein OPN in HCC.

Globular adiponectin acts as a melanogenic signal in human epidermal melanocytes

BACKGROUND

Adiponectin is an adipocyte-derived cytokine that circulates as a full-length protein and a fragment containing the globular domain of adiponectin (gAd). A recent study has reported the antimelanogenic effects of full-length adiponectin.

OBJECTIVES

To examine the involvement of gAd in melanogenesis and its mechanisms of action.

METHODS

The effects of gAd on melanogenesis and its mechanisms of action were investigated in human epidermal melanocytes and reconstructed epidermis, including melanin content, cellular tyrosinase activity, cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activity, expression and phosphorylation of signalling molecules.

RESULTS

Exogenous gAd increased melanin content, and the mRNA levels of microphthalmia-associated transcription factor (MITF) and its downstream genes TRP1, but not TRP2, were increased by gAd. However, cAMP production and PKA activity were not affected by gAd. Moreover, attempts to elucidate the underlying mechanism behind the gAd-mediated effect revealed that gAd could regulate melanogenesis by upregulating MITF through phosphorylation of the cAMP response element-binding protein (CREB). In addition, upregulation of MITF was mediated by activation of adenosine monophosphate-activated protein kinase (AMPK)-p38 mitogen-activated protein kinase (MAPK) signalling. Taken together, these findings indicate that promotion of melanogenesis by gAd occurs through increased expression of MITF, which is mediated by activation of the AMPK-p38 MAPK-CREB pathway.

CONCLUSIONS

These findings suggest that gAd contributes to epidermal homeostasis via its effect on melanocyte biology, and products of adipose tissue could affect epidermal biology.

A Hitherto Undescribed Congenital Haemorrhagic Diathesis Probably Due to Fibrin Stabilizing Factor Deficiency

A new congenital haemorrhagic diathesis is described. It is characterized by the poor and slaw wound healing, profuse and long bleeding and by probable absence of spontaneous and joint bleeding. It is due to the deficiency of a factor which makes the fibrin clots insoluble in urea. This factor is probably the fibrin stabilizing factor of Laki and Lorand, although no proof of their identity can yet be given. The deficiency appears in both sexes and is probably an autosomal recessive disease.

MicroRNAs of miR-17-92 cluster increase gene expression by targeting mRNA-destabilization pathways

MicroRNAs (miRNAs) of the miR-17-92 cluster are overexpressed in human cancers, and their enforced expression is tumorigenic in mouse models. A number of genes are reported to be targets of these miRNAs and are implicated in their tumorigenic potential. However, the mode of action by miRNAs suggests that global analysis of their targets is required to understand their cellular roles. In this study, we globally analyzed AGO2-bound mRNAs and found that the miR-17-92 miRNAs coherently repress multiple targets involved in the destabilization of mRNA. While the miRNAs repress the expression of their targets, they increase stability and lengthen the poly-A tails of non-target mRNAs. Furthermore, the expression of BTG3, TOB1, CSNK1A1 and ANKRD52 is negatively correlated with the expression of the miR-17-92 cluster in cancer cell lines. Our results suggest that the miR-17-92 miRNAs promote tumorigenesis not only by repression of key regulators, but also by posttranscriptional increases of global gene expression.

Meine Doktoranden – Erinnerungen eines Doktorvaters

Während meiner 35 Jahre an der Universität Heidelberg habe ich 77 Doktoranden angeleitet und zur Promotion geführt. 28 junge Kollegen waren es in den 10 Jahren als leitender Oberarzt an der Heidelberger Dermatologie und nochmals 49 als Direktor der Dermatologischen Klinik an der Medizinischen Fakultät Mannheim der Universität Heidelberg. Die spezielle Situation der Doktoranden wird geschildert, die Inhalte der Arbeiten werden angesprochen und die Ausbeute, die Ernte also, sowie die Publikation ausgelesener Resultate.