(+)-Cyanidan-3-ol inhibits epidermoid squamous cell carcinoma growth via inhibiting AKT/mTOR signaling through modulating CIP2A-PP2A axis.

BACKGROUND: Despite recent advances in the treatment of squamous cell skin cancer (SCSC), the disease persists, and treatment resistance develops. Thus, identifying new targets and developing new therapeutic approaches showing low vulnerability to drug resistance is highly needed. PURPOSE: This study aimed to reveal a novel targeted phytotherapeutic strategy for SCSC treatment alone or in combination with standard targeted anticancer molecules. STUDY DESIGN: A library of natural products was utilized to identify molecules that inhibit the growth of skin cancer cells. The anticancer potential of the selected compound was evaluated in human skin squamous carcinoma models, in vitro and in vivo. A comprehensive ingenuity pathway analysis (IPA) strategy and molecular biology technology was adopted to investigate the therapeutic mechanisms in human SCSC. METHODS: The Matrigel invasion chamber, foci formation and soft agar colony formation assays were employed to study the cells invasion and migration potential in vitro. In vivo antitumor effects were evaluated in DMBA/TPA-induced skin papilloma and A431 human skin squamous carcinoma xenograft tumor models. An integrative IPA was employed to identify mechanisms and protein targets in human SCSC.Compounds synergies were determined by the bliss model and evaluated using human SCSC cell lines and xenograft tumors. Histological staining, immunofluorescence imaging, real-time PCR, Western blots, and flow cytometric analyses were employed to analyze apoptosis and cell signaling mechanisms. RESULTS: We identified (+)-cyanidan-3-ol (CD-3) as a selective compound for inhibiting the growth of SCSC cell lines. CD-3 inhibited tumor growth and burden without apparent toxicity and prolonged the survival of tumor-bearing mice. CD-3 inhibitory effects on SCSC growth are mediated via cell cycle arrest and caspase-dependent apoptosis induction. Mechanistic studies showed that CD-3 activates PP2A via inhibiting CIP2A and produces tumor growth inhibitory effects via promoting dephosphorylation of oncogenic AKT/mTOR signaling proteins in SCSC cells and xenograft tumors in a PP2A dependent manner. Furthermore, the combination of CD-3 and mTOR inhibitors (mTORi) synergistically reduced oncogenic phenotypes. CONCLUSIONS: Our study suggests that PP2A activation is an effective strategy for SCSC treatment and the CD-3 and mTORi combination may serve as a promising treatment for SCSC.

Topical (+)-catechin emulsified gel prevents DMBA/TPA-induced squamous cell carcinoma of the skin by modulating antioxidants and inflammatory biomarkers in BALB/c mice.

An emulsified gel of (+)-catechin was developed and evaluated topically against 7,12-dimethylbenz(a)anthracene-induced and 12-O-tetradecanoylphorbol-13-acetate-promoted (DMBA-induced and TPA-promoted) squamous cell carcinoma of the skin in BALB/c mice. The biological evaluation outcome indicated that the (+)-catechin emulsified gel increased the activity of oxidative stress biomarkers glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx), whereas it decreased the level of malondialdehyde (MDA). The mechanistic study showed that genes implicated in the inflammation and cancer, such as cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-κB), and inducible nitric-oxide synthase (iNOS), were down-regulated by (+)-catechin emulsified gel while inhibiting an inflammatory mediator prostaglandin E2 (PGE2). The (+)-catechin emulsified gel further suppressed the activity of pro-inflammatory cytokines, viz. tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and interleukin-6 (IL-6). The in vitro permeation study revealed that release of (+)-catechin from an emulsified gel base reached a steady state after 6 h, while pH of the entire emulsified gel was found to be between 6.2 and 6.5 that falls well within the normal pH range of the skin.

Novel dual inhibitors of nuclear factor-kappa B (NF-κB) and cyclooxygenase- 2 (COX-2): synthesis, in vitro anticancer activity and stability studies of lantadene-non steroidal anti-inflammatory drug (NSAID) conjugates.

The activation of transcription factors nuclear factor-kappa B (NF-κ B) and cyclooxygenase-2 (COX-2) is critical in cancer; they act synergistically in promoting tumor growth, survival, and resistance to chemotherapy. Thus, combined targeting of NF-κ B and COX-2 present an opportunity for synergistic anticancer efficacy. The ester prodrugs of pentacyclic triterpenoids reduced lantadene A (3), B (4), and its congener 22ß-hydroxyoleanonic acid (5) with various non steroidal anti-inflammatory drugs (NSAIDs) present a novel approach. The ester prodrugs of 3 and 4 with diclofenac showed promising dual inhibition of NF-κ B and COX-2. The lead prodrugs 14 and 15 exhibited inhibition of inhibitor of nuclear factor-kappa B kinaseß (IKKß) in the single-digit micromolar range and at the same time, prodrugs 14 and 15 showed marked cytotoxicity against A549 lung cancer cell line with IC(50s) 0.15 and 0.42 µM, respectively. The prodrugs 14 and 15 exhibited stability in the acidic pH and were hydrolyzed readily in the human blood plasma to release the active parent moieties. Thus, we have synthesized novel hybrid compounds to target both NF-κ B and COX-2 via a prodrug approach, leading to promising anticancer candidates.