A Novel Sulforaphane-Regulated Gene Network in Suppression of Breast Cancer-Induced Osteolytic Bone Resorption

Withaferin A inhibits breast cancer-induced osteoclast differentiation

Bone is the most prone to metastatic spread of breast cancer cells for each subtype of the disease. Bone metastasis-related complications including severe pain and pathological fractures affect patients' quality of life. Current treatment options including surgery, radiation, and bone-targeted therapies (e.g., bisphosphonates) are costly or have serious adverse effects such as renal toxicity and osteonecrosis of the jaws. Therefore, a safe, inexpensive, and efficacious agent for prevention of breast cancer bone metastasis is urgently needed. Our previously published RNA sequencing analysis revealed that many genes implicated in bone remodeling and breast cancer bone metastasis were significantly downregulated by treatment with withaferin A (WA), which is a promising cancer chemopreventive agent derived from a medicinal plant (Withania somnifera). The present study investigated whether WA inhibits breast cancer induction of osteoclast differentiation. At plasma achievable doses, WA treatment inhibited osteoclast differentiation (osteoclastogenesis) induced by three different subtypes of breast cancer cells (MCF-7, SK-BR-3, and MDA-MB-231). WA and the root extract of W. somnifera were equally effective for inhibition of breast cancer induction of osteoclast differentiation. This inhibition was accompanied by suppression of interleukin (IL)-6, IL-8, and receptor activator of nuclear factor-κB ligand, which are pivotal osteoclastogenic cytokines. The expression of runt-related transcription factor 2, nuclear factor-κB, and SOX9 transcription factors, which positively regulate osteoclastogenesis, was decreased in WA-treated breast cancer cells as revealed by confocal microscopy and/or immunoblotting. Taken together, these data suggest that WA could be a promising agent for prevention of breast cancer-induced bone metastasis.

Molecular Pathways Related to Sulforaphane as Adjuvant Treatment: A Nanomedicine Perspective in Breast Cancer

Because cancer is a multifactorial disease, it is difficult to identify the specific agents responsible for the disease's progression and development, but lifestyle and diet have been shown to play a significant role. Diverse natural compounds are demonstrating efficacy in the development of novel cancer therapies, including sulforaphane (1-isothiocyanate-4-(methylsulfinyl)butane), a compound found in broccoli and other cruciferous vegetables that promotes key biological processes such as apoptosis, cell cycle arrest, autophagy, and suppression of key signalling pathways such as the PI3K/AKT/mTOR pathway in breast cancer cells. However, one of the primary challenges with sulforaphane treatment is its low solubility in water and oral bioavailability. As a consequence, several investigations were conducted using this component complexed in nanoparticles, which resulted in superior outcomes when combined with chemotherapy drugs. In this study, we discuss the properties and benefits of sulforaphane in cancer therapy, as well as its ability to form complexes with nanomolecules and chemotherapeutic agents that synergize the antitumour response in breast cancer cells.

Reactive sulfur and selenium species in the regulation of bone homeostasis

Reactive oxygen species (ROS) are important modulators of physiological signaling and play important roles in bone tissue regulation. Both reactive sulfur species (RSS) and reactive selenium species (RSeS) are involved in ROS signaling, and recent work suggests RSS and RSeS involvement in the regulation of bone homeostasis. For example, RSS can promote osteogenic differentiation and decrease osteoclast activity and differentiation, and the antioxidant activity of RSeS play crucial roles in balancing bone remodeling. Here, we outline current research progress on the application of RSS and RSeS in bone disease and regeneration. Focusing on these investigations, we highlight different methods, tools, and sources of RSS and RSeS, and we also highlight future opportunities for delivery of RSS and RSeS in biological environments relating to bone.

Mediterranean Diet Food Components as Possible Adjuvant Therapies to Counteract Breast and Prostate Cancer Progression to Bone Metastasis

Bone metastasis is a serious and often lethal complication of particularly frequent carcinomas, such as breast and prostate cancers, which not only reduces survival but also worsens the patients’ quality of life. Therefore, it is important to find new and/or additional therapeutic possibilities that can counteract the colonization of bone tissue. High adherence to the Mediterranean diet (MD) is effective in the prevention of cancer and improves cancer patients’ health, thus, here, we considered its impact on bone metastasis. We highlighted some molecular events relevant for the development of a metastatic phenotype in cancer cells and the alterations of physiological bone remodeling, which occur during skeleton colonization. We then considered those natural compounds present in MD foods with a recognized role to inhibit or reverse the metastatic process both in in vivo and in vitro systems, and we reported the identified mechanisms of action. The knowledge of this bioactivity by the dietary components of the MD, together with its wide access to all people, could help not only to maintain healthy status but also to improve the quality of life of patients with bone metastases.

OSU-03012 Disrupts Akt Signaling and Prevents Endometrial Carcinoma Progression in vitro and in vivo

Purpose

OSU-03012 is a celecoxib derivative lacking cyclooxygenase-2 inhibitory activity and a potent PDK1 inhibitor which has been shown to inhibit tumor growth in various ways. However, the role of OSU-03012 in endometrial carcinoma (EC) in which the PI3K/Akt signaling pathway highly activated has not been studied. Here, we determined the potency of OSU-03012 in suppressing EC progression in vitro and in vivo, and studied the underlined mechanisms.

Methods

The human EC Ishikawa and HEC-1A cells were used as the in vitro models. CCK8 assay and flow cytometry were conducted to evaluate cell proliferation, cell cycle progression, and apoptosis. The metastatic ability was evaluated using the transwell migration assay. The Ishikawa xenograft tumor model was used to study the inhibitory effects of OSU-03012 on EC growth in vivo. Western blot analysis was performed to evaluate expressions of the cell cycle and apoptosis associated proteins.

Results

OSU-03012 could inhibit the progression of EC both in vitro and in vivo by disrupting Akt signaling. It reduced the metastatic ability of EC, led to G2/M cell cycle arrest and induced apoptosis via the mitochondrial apoptosis pathway.

Conclusion

Our data indicated that OSU-03012 could inhibit the progression of EC in vitro and in vivo. It can potentially be used as the targeted drug for the treatment of EC by inhibiting Akt signaling.

Clinical efficiency of epigenetic drugs therapy in bone malignancies

A great interest in the scientific community is focused on the improvement of the cure rate in patients with bone malignancies that have a poor response to the first line of therapies. Novel treatments currently include epigenetic compounds or molecules targeting epigenetic-sensitive pathways. Here, we offer an exhaustive review of such agents in these clinical settings. Carefully designed preclinical studies selected several epigenetic drugs, including inhibitors of DNA methyltransferase (DNMTIs), such as Decitabine, histone deacetylase classes I-II (HDACIs), as Entinostat, Belinostat, lysine-specific histone demethylase (LSD1), as INCB059872 or FT-2102 (Olutasidenib), inhibitors of isocitrate dehydrogenases, and enhancer of zeste homolog 2 (EZH2), such as EPZ6438 (Tazemetostat) To enhance the therapeutic effect, the prevalent approach in phase II trial is the association of these epigenetic drug inhibitors, with targeted therapy or immune checkpoint blockade. Optimization of drug dosing and regimens of Phase II trials may improve the clinical efficiency of such novel therapeutic approaches against these devastating cancers.

Sulforaphane Inhibits Osteoclastogenesis via Suppression of the Autophagic Pathway

Previous studies have demonstrated that sulforaphane (SFN) is a promising agent against osteoclastic bone destruction. However, the mechanism underlying its anti-osteoclastogenic activity is still unclear. Herein, for the first time, we explored the potential role of autophagy in SFN-mediated anti-osteoclastogenesis in vitro and in vivo. We established an osteoclastogenesis model using receptor activator of nuclear factor kappa-β ligand (RANKL)-induced RAW264.7 cells and bone marrow macrophages (BMMs). Tartrate-resistant acid phosphatase (TRAP) staining showed the formation of osteoclasts. We observed autophagosomes by transmission electron microscopy (TEM). In vitro, we found that SFN inhibited osteoclastogenesis (number of osteoclasts: 22.67 ± 0.88 in the SFN (0) group vs. 20.33 ± 1.45 in the SFN (1 μM) group vs. 13.00 ± 1.00 in the SFN (2.5 μM) group vs. 6.66 ± 1.20 in the SFN (2.5 μM) group), decreased the number of autophagosomes, and suppressed the accumulation of several autophagic proteins in osteoclast precursors. The activation of autophagy by rapamycin (RAP) almost reversed the SFN-elicited anti-osteoclastogenesis (number of osteoclasts: 22.67 ± 0.88 in the control group vs. 13.00 ± 1.00 in the SFN group vs. 17.33 ± 0.33 in the SFN+RAP group). Furthermore, Western blot (WB) analysis revealed that SFN inhibited the phosphorylation of c-Jun N-terminal kinase (JNK). The JNK activator anisomycin significantly promoted autophagy, whereas the inhibitor SP600125 markedly suppressed autophagic activation in pre-osteoclasts. Microcomputed tomography (CT), immunohistochemistry (IHC), and immunofluorescence (IF) were used to analyze the results in vivo. Consistent with the in vitro results, we found that the administration of SFN could decrease the number of osteoclasts and the expression of autophagic light chain 3 (LC3) and protect against lipopolysaccharide (LPS)-induced calvarial erosion. Our findings highlight autophagy as a crucial mechanism of SFN-mediated anti-osteoclastogenesis and show that the JNK signaling pathway participates in this process.

Metabolism, absorption, and anti-cancer effects of sulforaphane: an update

Cancer is one of the most devastating diseases, and recently, a variety of natural compounds with preventive effects on cancer developments have been reported. Sulforaphane (SFN) is a potent anti-cancer isothiocyanate originating from Brassica oleracea (broccoli). SFN, mainly metabolized via mercapturic acid pathway, has high bioavailability and absorption. The present reviews mainly discussed the metabolism and absorption of SFN and newly discovered mechanistic understanding recent years for SFN's anti-cancer effects including promoting autophagy, inducing epigenetic modifications, suppressing glycolysis and fat metabolism. Moreover, its inhibitory effects on cancer stem cells and synergetic effects with other anti-cancer agents are also reviewed along with the clinical trials in this realm.

Preclinical Efficacy and Involvement of AKT, mTOR, and ERK Kinases in the Mechanism of Sulforaphane against Endometrial Cancer

Sulforaphane exerts anti-cancer activity against multiple cancer types. Our objective was to evaluate utility of sulforaphane for endometrial cancer therapy. Sulforaphane reduced viability of endometrial cancer cell lines in association with the G2/M cell cycle arrest and cell division cycle protein 2 (Cdc2) phosphorylation, and intrinsic apoptosis. Inhibition of anchorage-independent growth, invasion, and migration of the cell lines was associated with sulforaphane-induced alterations in epithelial-to-mesenchymal transition (EMT) markers of increased E-cadherin and decreased N-cadherin and vimentin expression. Proteomic analysis identified alterations in AKT, mTOR, and ERK kinases in the networks of sulforaphane effects in the Ishikawa endometrial cancer cell line. Western blots confirmed sulforaphane inhibition of AKT, mTOR, and induction of ERK with alterations in downstream signaling. AKT and mTOR inhibitors reduced endometrial cancer cell line viability and prevented further reduction by sulforaphane. Accumulation of nuclear phosphorylated ERK was associated with reduced sensitivity to the ERK inhibitor and its interference with sulforaphane activity. Sulforaphane induced apoptosis-associated growth inhibition of Ishikawa xenograft tumors to a greater extent than paclitaxel, with no evidence of toxicity. These results verify sulforaphane's potential as a non-toxic treatment candidate for endometrial cancer and identify AKT, mTOR, and ERK kinases in the mechanism of action with interference in the mechanism by nuclear phosphorylated ERK.