Acidic pH is a crucial intrinsic property of the microenvironment of most solid tumors. Hence, the use of pH sensitive tumor targeting nanoparticles is an attractive approach to enhance the therapeutic efficacy of anti-cancer agents in solid tumors. Chitosan nanoparticles (CHNPs) have been widely explored in the area of cancer drug delivery; nevertheless their true potential as a pH responsive targeted drug delivery vehicle in cancer therapy has not been deciphered yet as most of the research is limited to pH dependent stability and drug release. In the present study, we investigate the direct effect of pH in synergy with RGD peptide based targeting on the therapeutic efficacy of chitosan nanoparticles (RGD-CHNPs) in breast cancer. Furthermore, for the first time we performed a comprehensive study showing the anti-tumor, anti-migratory and anti-angiogenic effect of raloxifene (Rlx) loaded CHNPs in breast cancer. We prepared stable formulations of raloxifene encapsulated CHNPs and RGD-CHNPs by the nontoxic ionic gelation method. pH dependent studies revealed that NPs possess higher stability and zeta potential along with enhanced cellular uptake at acidic pH (as present in solid tumors) compared to physiological pH. Furthermore, RGD conjugation enhanced the in vitro cellular uptake of CHNPs in α_vβ₃ integrin expressing breast cancer cells and induced higher cellular apoptosis in breast cancer cells which was further augmented by lower pH. Moreover, Rlx-RGD-CHNPs significantly inhibited breast cancer cell migration and angiogenesis. In vivo studies showed that Cy5.5 conjugated RGD-CHNPs can distinctly visualize tumors and Rlx-RGD-CHNPs significantly inhibit breast tumor growth without causing any toxic effect to normal tissue as confirmed by hematology and blood biochemical studies. Therefore, RGD-CHNPs could potentially enhance the therapeutic efficacy of chemotherapeutic drugs due to the synergistic effect of pH responsiveness and tumor specific targeting in breast cancer.

Triple-negative breast cancer (TNBC) accounts for 15% of overall breast cancer. A lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2 receptor) makes TNBC more aggressive and metastatic. Wnt signaling is one of the important pathways in the cellular process; in TNBC it is aberrantly regulated, which leads to the progression and metastasis. In this study, we designed a therapeutic strategy using a combination of a low dose of paclitaxel and a Wnt signaling inhibitor (XAV939), and examined the effect of the paclitaxel-combined XAV939 treatment on diverse breast cancer lines including TNBC cell lines (MDA-MB-231, MDA-MB-468, and BT549) and ER+ve cell lines (MCF-7 and T-47D). The combination treatment of paclitaxel (20 nM) and XAV939 (10 µM) exerted a comparable therapeutic effect on MDA-MB-231, MDA-MB-468, BT549, MCF-7, and T-47D cell lines, relative to paclitaxel with a high dose (200 nM). The paclitaxel-combined XAV939 treatment induced apoptosis by suppressing Bcl-2 and by increasing the cleavage of caspases-3 and PARP. In addition, the in vivo results of the paclitaxel-combined XAV939 treatment in a mice model with the MDA-MB-231 xenograft further confirmed its therapeutic effect. Furthermore, the paclitaxel-combined XAV939 treatment reduced the expression of β-catenin, a key molecule in the Wnt pathway, which led to suppression of the expression of epithelial-mesenchymal transition (EMT) markers and angiogenic proteins both at mRNA and protein levels. The expression level of E-cadherin was raised, which potentially indicates the inhibition of EMT. Importantly, the breast tumor induced by pristane was significantly reduced by the paclitaxel-combined XAV939 treatment. Overall, the paclitaxel-combined XAV939 regimen was found to induce apoptosis and to inhibit Wnt signaling, resulting in the suppression of EMT and angiogenesis. For the first time, we report that our combination approach using a low dose of paclitaxel and XAV939 could be conducive to treating TNBC and an external carcinogen-induced breast cancer.

Psoriasis is a recurrent skin disease described as keratinocyte hyperproliferation and aberrant differentiation. Erianin, a bibenzyl compound extracted from Dendrobium chrysotoxum, has displayed antitumor and anti-angiogenesis effects. However, the effects of erianin on a human keratinocyte cell line (HaCaT) are not fully understood. In the present study, we explored the effect of erianin on proliferation and apoptosis in HaCaT cells. Our results indicated that treatment with erianin ranging from 12.5 nM to 50 nM inhibited proliferation and induced apoptosis of HaCaT cells. In addition, erianin-induced apoptosis was accompanied by elevated reactive oxygen species (ROS). The ROS scavenger N-acetyl-cysteine (NAC) attenuated this elevation. Moreover, treatment with erianin induced activation of the c-Jun N-terminal kinase (JNK)/c-Jun signaling pathway and suppressed the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, while pretreatment with NAC also reversed these effects. Collectively, these data demonstrated that erianin inhibited proliferation and induced apoptosis of HaCaT cells through ROS-mediated JNK/c-Jun and AKT/mTOR signaling pathways. Erianin could be recognized as a potential anti-psoriasis drug.

Osteoclasts are multinuclear giant cells that have unique ability to degrade bone. The search for new medicines that modulate the formation and function of osteoclasts is a potential approach for treating osteoclast-related bone diseases. Piceatannol (PIC) is a natural organic polyphenolic stilbene compound found in diverse plants with a strong antioxidant and anti-inflammatory effect. However, the effect of PIC on bone health has not been scrutinized systematically. In this study, we used RAW264.7, an osteoclast lineage of cells of murine macrophages, to investigate the effects and the underlying mechanisms of PIC on osteoclasts. Here, we demonstrated that PIC treatment ranging from 0 to 40 µM strongly inhibited osteoclast formation and bone resorption in a dose-dependent manner. Furthermore, the inhibitory effect of PIC was accompanied by the decrease of osteoclast-specific genes. At the molecular level, PIC suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2), NF-κB p65, IκBα and AKT. Besides, PIC promoted the apoptosis of mature osteoclasts by inducing caspase-3 expression. In conclusion, our results suggested that PIC inhibited RANKL-induced osteoclastogenesis and bone resorption by suppressing MAPK, NF-κB and AKT signalling pathways and promoted caspase3-mediated apoptosis of mature osteoclasts, which might contribute to the treatment of bone diseases characterized by excessive bone resorption.

The concept of liquid biopsy as an analysis tool for non-solid tissue carried out for the purpose of providing information about solid tumors was introduced approximately 20 years ago. Additional to the detection of circulating tumor cells (CTCs), the liquid biopsy approach quickly included the analysis of circulating tumor DNA (ctDNA) and other tumor-derived markers such as circulating cell-free RNA or extracellular vesicles. Liquid biopsy is a non-invasive technique for detecting multiple cancer-associated biomarkers that is easy to obtain and can reflect the characteristics of the entire tumor mass. Currently, ctDNA is the key component of the liquid biopsy approach from the point of view of the prognosis assessment, prediction, and monitoring of the treatment of non-small-cell lung cancer (NSCLC) patients. ctDNA in NSCLC patients carries variants or rearrangements that drive carcinogenesis, such as those in EGFR, KRAS, ALK, or ROS1. Due to advances in pharmacology, these variants are the subject of targeted therapy. Therefore, the detection of these variants has gained attention in clinical medicine. Recently, methods based on qPCR (ddPCR, BEAMing) and next-generation sequencing (NGS) are the most effective approaches for ctDNA analysis. This review addresses various aspects of the use of liquid biopsy with an emphasis on ctDNA as a biomarker in NSCLC patients.

Hepatocellular carcinoma (HCC) is a severe neoplastic disease associated with high morbidity and mortality rates. HCC is often detected at advanced stages leading to ineffective curative treatments. Recently, liquid biopsy has emerged as a non-invasive method to identify highly specific HCC biomarkers in bodily fluids such as blood, serum, urine, and saliva. Circulating cell-free nucleic acids (cfNAs), particularly cell-free DNA (cfDNA) and cell-free RNA (cfRNA), have become promising candidates for biomarkers in liquid biopsy applications. While cfDNA presented significant challenges, researchers have turned their attention to cfRNA, which can be efficiently identified through various methods and is considered a potential biomarker for cancer diagnosis and prognosis. This review primarily focuses on studies related to detecting various cfRNA in body fluids as biomarkers. The aim is to provide a summary of available information to assist researchers in their investigations and the development of new diagnostic and prognostic tools.