Sonic hedgehog signaling is associated with resistance to zoledronic acid in CD133high/CD44high prostate cancer stem cells

Translating preclinical insights into clinical strategies: Targeting cancer stem cells and stemness in prostate cancer

CSCs represent a unique group within the tumor microenvironment (TME) elevating the tumorigenesis. The cause of cancer recurrence can also be investigated in the function of CSCs possessing self-renewing capabilities and differentiation into various types of cells. Prostate cancer (PCa) is a malignant disease of the urogenital system characterized by aggressive behavior and heterogeneous nature due to the dysregulation of molecular pathways and the interactions among cells within the TME. The PCa can quickly become resistant to standard chemotherapy and other kinds of therapies such as radiotherapy along with ability to mediate immune evasion. The focus of biology has been on the molecular and cellular alterations in PCa. The CSCs have been recognized as potential biomarkers for predicting the outcome of prostate PCa. Furthermore, a positive correlation exists between CSCs and the metastatic growth and stemness of PCa. The existence of hypoxia enhances the stemness of PCa, and CSCs play a role in dormancy. Genomic and epigenetic elements, including non-coding RNAs, can influence CSCs and the advancement of PCa. Additionally, therapeutic agents and nanotechnology methods aimed at targeting CSCs have been developed to inhibit CSCs in PCa treatment.

Effects of 5-azacytidine and N6-methyladenosine combination on apoptosis and stemness in human breast cancer stem cells

BACKGROUND

This study investigates the combined effects of the epigenetic anticancer drug 5-azacytidine (5-Aza) and N6-methyladenosine (m6A) on breast cancer stem cells (CSCs) and normal breast epithelial cells. CSCs are characterized by their ability to self-renew, their resistance to conventional therapies, and their role in metastasis, presenting a significant challenge in breast cancer treatment.

METHODS AND RESULTS

The study utilized flow cytometry to isolate CD44 + /CD24low CSCs from MCF-7 breast cancer cells and evaluated these cells through spheroid formation assays. The results demonstrated that both 5-Aza and m6A, both individually and in combination, exert cytotoxic effects on CSCs, induce apoptosis, and reduce their migratory capacity. Importantly, these treatments did not produce similar effects on normal breast epithelial cells (MCF-10A), indicating selective action on CSCs. Gene expression analysis revealed that treatment with 5-Aza, m6A, and their combination altered the expression of key stem cell-related genes, including OCT4, NANOG, SOX2, and c-MYC, which are associated with CSC self-renewal and malignancy.

CONCLUSIONS

These findings suggest that epigenetic modulation through 5-Aza and m6A could effectively target CSCs, disrupting their ability to drive tumor progression and metastasis, particularly in aggressive breast cancer subtypes. This study highlights the potential of 5-Aza and m6A as a combinatorial therapeutic approach, offering a promising avenue for improving treatment outcomes in breast cancer patients, especially those with therapy-resistant disease. Further clinical investigation is needed to validate these findings and explore their therapeutic implications.

Effects of sulforaphane on prostate cancer stem cells-like properties: In vitro and molecular docking studies

The increasing incidence of prostate cancer worldwide has spurred research into novel therapeutics for its treatment and prevention. A critical factor contributing to its incidence and development is the presence of prostate cancer stem cells (PCSCs). Targeting PCSCs has become key in enhancing therapeutic and clinical outcomes of prostate cancer. Sulforaphane (SFN), a compound found in cruciferous vegetables, has shown effective antineoplastic activity in prostate cancer. Yet, its mechanisms of action in PCSCs remains unclear. In the present study, tumorsphere formation assay was used to isolate and enrich PCSCs from PC-3 cells. Our results found that SFN effectively reduced the activity of PCSCs, including the ability of tumorsphere formation, the number of CD133 positive cells, and the expression of PCSCs markers. Moreover, the data showed that SFN inhibited PCSCs through downregulating the activation of Wnt/β-catenin and hedgehog signaling pathways in PCSCs. Furthermore, the verification experiments showed that the activators of Wnt/β-catenin (LiCl) and hedgehog (purmorphamine) attenuated the effects of SFN on PCSCs, including the expression of stem cell markers, cell proliferation and apoptosis. Meanwhile, suppression of β-catenin or Smoothened enhanced the effects of SFN on PCSCs. In addition, molecular docking further indicated that SFN inhibited Wnt/β-catenin and hedgehog pathways by directly targeting β-catenin and Smoothened. Taken together, our results demonstrated that SFN targeted PCSCs through Wnt/β-catenin and hedgehog pathways to inhibit stemness and proliferation and induce apoptosis. Findings from this study could provide new insights into SFN as a dietary supplement or adjunct to chemotherapy.

Zoledronic Acid-Treated Rats Show Altered Jaw Histology and Gene Expression in Nonexposed Medication-Related Osteonecrosis of the Jaws

BACKGROUND

Diagnosis and management of medication-related osteonecrosis of the jaws (MRONJ) prior to clinical exposure induced by trauma may lead to improved patient management. Currently, few studies have examined early histologic and molecular MRONJ-related changes in the jaws.

PURPOSE

This study aimed to identify histological and gene expression changes in the maxilla and mandible of Sprague-Dawley (SD) rats after zoledronic acid (ZA) treatment.

STUDY DESIGN, SETTING, AND SAMPLE

This was an in vivo animal study. The experiments were conducted in the laboratory at the Stomatology Hospital of Tianjin Medical University. A total of 12 SD rats were included.

PREDICTOR VARIABLE

The predictor variable was ZA exposure. Twelve SD rats were divided into 2 groups: experimental (n = 6) and control (n = 6), and they were intraperitoneally injected with ZA and saline, respectively.

MAIN OUTCOME VARIABLE

The outcome variables were histological and molecular changes. The maxilla, mandible, and ilium bone tissue samples were examined using Masson's trichrome and hematoxylin-eosin staining. Gene expression changes were identified using transcriptome sequencing, the Kyoto encyclopedia of genes and genomes, and gene interactome network analysis. The key changes were validated using the quantitative real-time polymerase chain reaction and immunohistochemistry.

COVARIATES

None.

ANALYSES

The t-test, χ2 test, and Fisher's exact probability method were used for statistical analyses using the Statistical Package for the Social Sciences software (version 26.0).

RESULTS

All animals remained healthy during the experiments. Histological staining revealed that the percentage of empty bone lacunae in the maxilla and mandible was significantly higher than that in the ilium (P < .01). In total, 552 genes were screened using transcriptome sequencing. The sonic hedgehog (Shh) signaling pathway was highly enriched. The key gene for the Shh interaction was distal-less homeobox 5. The Shh, distal-less homeobox 5, and bone morphogenetic protein 2 genes and protein expression levels in the maxilla and mandible were higher in the experimental group than in the control group (P < .05).

CONCLUSION AND RELEVANCE

MRONJ-induced osteonecrosis and gene expression changes precede trauma-induced clinical changes in the SD rat model. These findings may provide additional support for timely and clinically early diagnosis and intervention.

Biomolecular fingerprints of the effect of zoledronic acid on prostate cancer stem cells: Comparison of 2D and 3D cell culture models

Revealing the potential of candidate drugs against different cancer types without disrupting normal cells depends on the drug mode of action. In the current study, the drug response of prostate cancer stem cells (PCSCs) to zoledronic acid (ZOL) grown in two-dimensional (2D) and three-dimensional (3D) culture systems was compared using Fourier transform-infrared (FT-IR) spectroscopy which is a vibrational spectroscopic technique, supporting by biochemical assays and imaging techniques. Based on our data, in 2D cell culture conditions, the ZOL treatment of PCSCs isolated according to both C133 and CD44 cell surface properties induced early/late apoptosis and suppressed migration ability. The CD133 gene expression and protein levels were altered, depending on culture systems. CD133 expression was significantly reduced in 2D cells upon ZOL treatment. FT-IR data revealed that the integrity, fluidity, and ordering/disordering states of the cell membrane and nucleic acid content were altered in both 2D and 3D cells after ZOL treatment. Regular protein structures decrease in 2D cells while glycogen and protein contents increase in 3D cells, indicating a more pronounced cytotoxic effect of ZOL for 2D cells. Untreated 3D PCSCs exhibited an even different spectral profile associated with IR signals of lipids, proteins, nucleic acids, and glycogen in comparison to untreated 2D cells. Our study revealed significant differences in the drug response and cellular constituents between 2D and 3D cells. Exploring molecular targets and/or drug-action mechanisms is significant in cancer treatment approaches; thus, FT-IR spectroscopy can be successfully applied as a novel drug-screening method in clinical research.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

TEAD3 inhibits the proliferation and metastasis of prostate cancer via suppressing ADRBK2

TEAD3 acts as a transcription factor in many tumors to promote tumor occurrence and development. But in prostate cancer (PCa), it appears as a tumor suppressor gene. Recent studies have shown that this may be related to subcellular localization and posttranslational modification. We found that TEAD3 was down-expressed in PCa. Immunohistochemistry of clinical PCa specimens confirmed that TEAD3 expression was the highest in benign prostatic hyperplasia (BPH) tissues, followed by primary PCa tissues, and the lowest in metastatic PCa tissues, and its expression level was positively correlated with overall survival. MTT assay, clone formation assay, and scratch assay confirmed that overexpression of TEAD3 could significantly inhibit the proliferation and migration of PCa cells. Next-generation sequencing results indicated that Hedgehog (Hh) signaling pathway was significantly inhibited after overexpression of TEAD3. Rescue assays suggested that ADRBK2 could reverse the proliferation and migration ability caused by overexpression of TEAD3. TEAD3 is downregulated in PCa and associated with poor patient prognosis. Overexpression of TEAD3 inhibits the proliferation and migration ability of PCa cells via restraining the mRNA level of ADRBK2. These results indicate that TEAD3 was down-expressed in PCa patients and was positively correlated with a high Gleason score and poor prognosis. Mechanistically, we found that the upregulation of TEAD3 inhibits the proliferation and metastasis of prostate cancer by inhibiting the expression of ADRBK2.

Anti-Cancer Stem-Cell-Targeted Therapies in Prostate Cancer

Prostate cancer (PCa) is the second-most commonly diagnosed cancer in men around the world. It is treated using a risk stratification approach in accordance with the National Comprehensive Cancer Network (NCCN) in the United States. The main treatment options for early PCa include external beam radiation therapy (EBRT), brachytherapy, radical prostatectomy, active surveillance, or a combination approach. In those with advanced disease, androgen deprivation therapy (ADT) is considered as a first-line therapy. However, the majority of cases eventually progress while receiving ADT, leading to castration-resistant prostate cancer (CRPC). The near inevitable progression to CRPC has spurred the recent development of many novel medical treatments using targeted therapies. In this review, we outline the current landscape of stem-cell-targeted therapies for PCa, summarize their mechanisms of action, and discuss avenues of future development.

Prostate Cancer Stem Cells: Clinical Aspects and Targeted Therapies

Despite decades of research and successful improvements in diagnosis and therapy, prostate cancer (PC) remains a major challenge. In recent years, it has become clear that PC stem cells (PCSCs) are the driving force in tumorigenesis, relapse, metastasis, and therapeutic resistance of PC. In this minireview, we discuss the impact of PCSCs in the clinical practice. Moreover, new therapeutic approaches to combat PCSCs are presented with the aim to achieve an improved outcome for patients with PC.

Garcinone C Suppresses Tumorsphere Formation and Invasiveness by Hedgehog/Gli1 Signaling in Colorectal Cancer Stem-like Cells

Hyperactivation of hedgehog signaling occurs in colorectal cancer stem-like cells (CSCs), a rare subpopulation, potentially involved in metastasis, chemotherapy resistance, and cancer relapse. Garcinone C, a xanthone isolated from mangosteen (Garcinia mangostana), suppresses colorectal cancer in vivo and in vitro by inhibiting Gli1-dependent noncanonical hedgehog signaling. Herein, we investigated the effect of garcinone C on cancer stemness and invasiveness in colorectal cancer; Gli1 was noted as pivotal in maintaining stemness and invasiveness in HCT116 and HT29 CSCs. Garcinone C inhibited the proliferation and self-renewal of HCT116 and HT29 CSCs. Colon cancer stemness markers such as CD44, CD133, ALDH1, and Nanog were significantly decreased by garcinone C. Computational studies showed that garcinone C showed a high affinity with the Gli1 protein ZF domain by forming hydrogen bonds with amino acid residues of ASP244, ARG223, and ASP216. Besides, MG132 blocked the effects of garcinone C on Gli1. Thus, garcinone C suppressed colorectal CSCs by binding to Gli1 and enhancing its degradation. MMP2 and MMP9 levels, invasive-related markers, were increased in HCT116 CSCs but decreased by garcinone C. E-cadherin level was reduced in HCT116 CSCs, while the presence of garcinone C was restored. Garcinone C inhibited the proliferation and invasiveness of colorectal CSCs by targeting Gli1-dependent Hh signaling. Garcinone C may be a potent natural agent against colorectal cancer relapse.

"Double hit" strategy: Removal of sialic acid from the dendritic cell surface and loading with CD44+/CD24-/low cell lysate inhibits tumor growth and metastasis by targeting breast cancer stem cells

Cancer stem cells (CSCs), which represent the root cause of resistance to conventional treatments, recurrence, and metastasis, constitute the critical point of failure in cancer treatments. Targeting CSCs with dendritic cell (DC)-based vaccines have been an effective strategy, but sialic acids on the surface of DCs limit the interaction with loaded antigens. We hypothesized that removal of sialic acid moieties on immature DCs (iDCs) could significantly affect DC-CSC-antigen loading, thereby leading to DC maturation and improving immune recognition and activity. The lysate of CD44⁺/CD24^-/low breast CSCs (BCSCs) was pulsed with sialidase-treated DCs to obtain mature dendritic cells (mDCs). The roles of cytoskeletal elements in antigen uptake and dendritic cell maturation were determined by immunofluorescence staining, flow cytometry, and cytokine measurement, respectively. To test the efficacy of the vaccine in vivo, CSCs tumor-bearing mice were immunized with iDC or mDC. Pulsing DCs with antigen increased the expression levels of actin, gelsolin, talin, WASp, and Arp2, especially in podosome-like regions. Compared with iDCs, mDCs expressed high levels of CD40, CD80, CD86 costimulatory molecules and increased IL-12 production. Vaccination with mDC: i) increased CD8+ and CD4 + T-cell numbers, ii) prevented tumor growth with anti-mitotic activity and apoptotic induction, iii) suppressed metastasis by decreasing Snail, Slug, and Twist expressions. This study reveals for the first time that sialic acid removal and loading with CSC antigens induces significant molecular, morphological, and functional changes in DCs and that this new DC identity may be considered for future combined immunotherapy strategies against breast tumors.