Identification of Anticancer Peptides from the Genome of Candida albicans: in Silico Screening, in Vitro and in Vivo Validations.

Anticancer peptides (ACPs) are promising future therapeutics, but their experimental discovery remains time-consuming and costly. To accelerate the discovery process, we propose a computational screening workflow to identify, filter, and prioritize peptide sequences based on predicted class probability, antitumor activity, and toxicity. The workflow was applied to identify novel ACPs with potent activity against colorectal cancer from the genome sequences of Candida albicans. As a result, four candidates were identified and validated in the HCT116 colon cancer cell line. Among them, PCa1 and PCa2 emerged as the most potent, displaying IC50 values of 3.75 and 56.06 µM, respectively, and demonstrating a 4-fold selectivity for cancer cells over normal cells. In the colon xenograft nude mice model, the administration of both peptides resulted in substantial inhibition of tumor growth without causing significant adverse effects. In conclusion, this work not only contributes a proven computational workflow for ACP discovery but also introduces two peptides, PCa1 and PCa2, as promising candidates poised for further development as targeted therapies for colon cancer. The method as a web service is available at https://app.cbbio.online/acpep/home and the source code at https://github.com/cartercheong/AcPEP_classification.git.

Nanoenabled intracellular zinc bursting for efficacious reversal of gefitinib resistance in lung cancer.

Following the identification of specific epidermal growth factor receptor (EGFR)-activating mutations, gefitinib, one of the first-generation tyrosine kinase inhibitors (TKIs), has proven efficacious in targeting NSCLC that is driven by specific EGFR-activating mutations. However, most patients who initially respond to gefitinib, develop acquired resistance. In the current study, we devised a novel strategy to enhance the efficacy of gefitinib. We developed a simple and effective, nano-interrupter termed zeolitic imidazolate framework-8@Gefitinib@hyaluraonic nanoparticle (ZIF-8@G@HA NP). This nanoparticle was prepared by loading gefitinib onto a ZIF-8 nanoplatform followed by coating with hyaluronic acid (HA). The burst of Zn2+ release triggered by pH-sensitive degradation of ZIF-8@G@HA NPs was shown to enhance the efficacy of gefitinib in parental lung carcinoma HCC827 cells and overcame acquired gefitinib resistance in gefitinib drug resistant (GDR) HCC827 cells. We found that when treated with ZIF-8@G@HA NPs, Zn2+ acts synergistically with gefitinib via increased apoptosis in both parental and GDR HCC827 cells. Consistently, this in vitro activity was correlated with in vivo tumor growth inhibition. Interestingly, GDR cells were more sensitive to Zn2+ when compared with parental cells. We further found that ZIF-8 NPs overcame gefitinib resistance by triggering reactive oxygen species (ROS) generation and consequent cell cycle arrest at the G2/M phase, resulting in cancer cell apoptosis. Zn2+ was also found to block P-gp activity, facilitating the accumulation of gefitinib in GDR cells, thus enhancing the anti-tumor efficacy of gefitinib resulting in reversal of gefitinib resistance. Thus, this study offers a novel and promising strategy to surmount acquired gefitinib resistance via cell cycle arrest at the G2/M phase by facilitating gefitinib accumulation in GDR cells.

Discovery and analysis of a novel antimicrobial peptide B1AW from the skin secretion of Amolops wuyiensis and improving the membrane-binding affinity through the construction of the lysine-introduced analogue.

In the development and study of antimicrobial peptides (AMPs), researchers have kept a watchful eye on peptides from the brevinin family because of their extensive antimicrobial activities and anticancer potency. In this study, a novel brevinin peptide was isolated from the skin secretions of the Wuyi torrent frog, Amolops wuyiensis (A. wuyiensisi), named B1AW (FLPLLAGLAANFLPQIICKIARKC). B1AW displayed anti-bacterial activity against Gram-positive bacteria Staphylococcus aureus (S. aureus), methicillin-resistant Staphylococcus aureus (MRSA), and Enterococcus faecalis (E. faecalis). B1AW-K was designed to broaden the antimicrobial spectrum of B1AW. The introduction of a lysine residue generated an AMP with enhanced broad-spectrum antibacterial activity. It also displayed the ability to inhibit the growth of human prostatic cancer PC-3, non-small lung cancer H838, and glioblastoma cancer U251MG cell lines. In molecular dynamic (MD) simulations, B1AW-K had a faster approach and adsorption to the anionic membrane than B1AW. Therefore, B1AW-K was considered a drug prototype with a dual effect, which deserves further clinical investigation and validation.

The tick saliva peptide HIDfsin2 promotes the tick-borne virus SFTSV replication in vitro by enhancing p38 signal pathway.

Pathogens co-evolved with ticks to facilitate blood collection and pathogen transmission. Although tick saliva was recently found to be rich in bioactive peptides, it is still elusive which saliva peptide promotes virus transmission and which pathways are invovled. Here, we used a saliva peptide HIDfsin2 and a severe fever with thrombocytopenia syndrome virus (SFTSV) both carried by the tick Haemaphysalis longicornis to elucidate the relationship between tick saliva components and tick-borne viruses. HIDfsin2 was found to promote the replication of SFTSV in a dose-dependent manner in vitro. HIDfsin2 was further revealed to MKK3/6-dependently magnify the activation of p38 MAPK. The overexpression, knockdown and phosphorylation site mutation of p38α indicated that p38 MAPK activation facilitated SFTSV infection in A549 cells. Moreover, the blockade of p38 MAPK activation significantly suppressed SFTSV replication. Differently, HIDfsin2 or pharmacological inhibition of p38 MAPK activation had no effect on a mosquito-borne Zika virus (ZIKV). All these results showed that HIDfsin2 specifically promoted SFTSV replication through the MKK3/6-dependent enhancement of p38 MAPK activation. Our study provides a new perspective on the transmission of tick-borne viruses under natural conditions, and supports that the blockade of p38 MAPK activation can be a promising strategy against the mortal tick-borne virus SFTSV.

The real-time detection of acupuncture-induced extracellular ATP mobilization in acupoints and exploration of its role in acupuncture analgesia.

Our and in vitro studies had confirmed that mechanosensitive ATP release and accumulation in acupoints was elicited by acupuncture (AP), which might be a pivotal step for triggering AP analgesia. But to date, the dynamics of extracellular ATP (eATP) in the interstitial space during AP process was poorly known, mainly due to the low temporal resolution of the current detection approach. This study attempted to capture rapid eATP signals in vivo in the process of needling, and further explored the role of this eATP mobilization in initiating AP analgesic effect. Ipsilateral 20-min needling was applied on Zusanli acupoint (ST36) of complete Freund's adjuvant (CFA)-induced ankle arthritis rats. Pain thresholds were assessed in injured-side hindpaws. eATP in the interstitial space was microdialyzed and real-time quantified by luciferin-luciferase assay at 1-min interval with the aid of the microfluid chip. We revealed in behavioral tests that modulation of eATP levels in ST36 influenced AP analgesic effect on ankle arthritis. A transient eATP accumulation was induced by needling that started to mobilize at 4 min, climbed to the peak of 11.21 nM within 3.25 min and gradually recovered. Such AP-induced eATP mobilization was significantly impacted by ankle inflammation, needling depth, needle manipulation, and the presence of local ecto-nucleotidases. This work reveals that needling elicits a transient eATP mobilization in acupoints, which contributes to initiating AP analgesia. This study will help us better understand the peripheral mechanism of AP analgesia and guide clinicians to optimize the needle manipulations to improve AP efficacy.

Development of Marine-Derived Compounds for Cancer Therapy.

Cancer has always been a threat to human health with its high morbidity and mortality rates. Traditional therapy, including surgery, chemotherapy and radiotherapy, plays a key role in cancer treatment. However, it is not able to prevent tumor recurrence, drug resistance and treatment side effects, which makes it a very attractive challenge to search for new effective and specific anticancer drugs. Nature is a valuable source of multiple pharmaceuticals, and most of the anticancer drugs are natural products or derived from them. Marine-derived compounds, such as nucleotides, proteins, peptides and amides, have also shed light on cancer therapy, and they are receiving a fast-growing interest due to their bioactive properties. Their mechanisms contain anti-angiogenic, anti-proliferative and anti-metastasis activities; cell cycle arrest; and induction of apoptosis. This review provides an overview on the development of marine-derived compounds with anticancer properties, both their applications and mechanisms, and discovered technologies.

Mechanosensitive TRPV4 Channel-Induced Extracellular ATP Accumulation at the Acupoint Mediates Acupuncture Analgesia of Ankle Arthritis in Rats.

(1) Background: Acupuncture (AP) is a safe and effective analgesic therapy. Understanding how fine needles trigger biological signals can help us optimize needling manipulation to improve its efficiency. Adenosine accumulation in treated acupoints is a vital related event. Here, we hypothesized that extracellular ATP (eATP) mobilization preceded adenosine accumulation, which involved local activation of mechanosensitive channels, especially TRPV4 protein. (2) Methods: AP was applied at the injured-side Zusanli acupoint (ST36) of acute ankle arthritis rats. Pain thresholds were assessed in injured-side hindpaws. eATP in microdialysate from the acupoints was determined by luminescence assay. (3) Results: AP analgesic effect was significantly suppressed by pre-injection of GdCl3 or ruthenium red in ST36, the wide-spectrum inhibitors of mechanosensitive channels, or by HC067047, a specific antagonist of TRPV4 channels. Microdialysate determination revealed a needling-induced transient eATP accumulation that was significantly decreased by pre-injection of HC067047. Additionally, preventing eATP hydrolysis by pre-injection of ARL67156, a non-specific inhibitor of ecto-ATPases, led to the increase in eATP levels and the abolishment of AP analgesic effect. (4) Conclusions: These observations indicate that needling-induced transient accumulation of eATP, due to the activation of mechanosensitive TRPV4 channels and the activities of ecto-ATPases, is involved in the trigger mechanism of AP analgesia.

Integrative gene expression profiling reveals that dysregulated triple microRNAs confer paclitaxel resistance in non-small cell lung cancer via co-targeting MAPT.

BACKGROUND: Paclitaxel has shown significant anti-tumor activity against non-small cell lung cancer (NSCLC); however, resistance to paclitaxel frequently occurs and represents a significant clinical problem and its underlying molecular mechanism remains elusive. METHODS: Long-term treatment of culture cell with paclitaxel was carried out to mimic the development of acquired drug resistance in NSCLC. Cell proliferation and clonogenic assay and apoptosis evaluation were carried out to determine the efficacy of paclitaxel on NSCLC cells. Western blot analyses were performed to determine the expression and activation of proteins. Apoptosis enzyme-linked immunosorbent assay was used to quantify cytoplasmic histone-associated DNA fragments. Microarray analyses were applied to explore both mRNA and miRNA expression profiles in NSCLC cells followed by integrative analysis. qRT-PCR was carried out to verify the differentially expressed mRNAs and miRNAs. RESULTS: The expression of 652 genes was shown to be changed at least 2-fold in paclitaxel-resistant NSCLC (H460_TaxR) cells with 511 upregulated and 141 downregulated as compared with that in parental H460 cells. The differentially expressed genes were functionally enriched in regulating the cell proliferation, cell death, and response to endogenous stimulus, and clustered in pathways such as cancer and signaling by the G protein-coupled receptor (GPCR). Moreover, 43 miRNAs were shown to be differentially expressed in H460_TaxR cells with 15 upregulated and 28 downregulated as compared with parental H460 cells. A total of 289 pairs of miRNA-potential target gene were revealed in H460_TaxR cells by bioinformatics analysis. Furthermore, integrative analysis of miRNAs and gene expression profiles revealed that dysregulated miR-362-3p, miR-766-3p, and miR-6507-3p might confer paclitaxel resistance in NSCLC via targeting MAPT simultaneously. CONCLUSION: Our findings suggested that specific manipulation of MAPT-targeting miRNAs may be a novel strategy to overcome paclitaxel resistance in patients with NSCLC especially large-cell lung carcinoma.

Valproic acid exhibits anti-tumor activity selectively against EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer via induction of ErbB family members-targeting microRNAs.

BACKGROUND: Deregulated ErbB signaling plays an important role in tumorigenesis of pancreatic cancer. However, patients with pancreatic cancer benefit little from current existed therapies targeting the ErbB signaling. Here, we explore the potential anti-tumor activity of Valproic acid against pancreatic cancer via targeting ErbB family members. METHODS: Cell viability assay and apoptosis evaluation were carried out to determine the efficacy of VPA on pancreatic cancer cells. Western blot analyses were performed to determine the expression and activation of proteins. Apoptosis enzyme-linked immunosorbent assay was used to quantify cytoplasmic histone associated DNA fragments. Lentiviral expression system was used to introduce overexpression of exogeneous genes or gene-targeting short hairpin RNAs (shRNAs). qRT-PCR was carried out to analyze the mRNAs and miRNAs expression levels. Tumor xenograft model was established to evaluate the in vivo anti-pancreatic cancer activity of VPA. RESULTS: VPA preferentially inhibited cell proliferation/survival of, and induced apoptosis in EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer cells within its clinically achievable range [40~100 mg/L (0.24~0.6 mmol/L)]. Mechanistic investigations revealed that VPA treatment resulted in simultaneous significant down-regulation of EGFR, ErbB2, and ErbB3 in pancreatic cancer cells likely via induction of ErbB family members-targeting microRNAs. Moreover, the anti-pancreatic cancer activity of VPA was further validated in tumor xenograft model. CONCLUSIONS: Our data strongly suggest that VPA may be added to the treatment regimens for pancreatic cancer patients with co-overexpression of the ErbB family members.

Mesenchymal stem cells drive paclitaxel resistance in ErbB2/ErbB3-coexpressing breast cancer cells via paracrine of neuregulin 1.

We had previously demonstrated that increased expression of ErbB3 is required for ErbB2-mediated paclitaxel resistance in breast cancer cells. In the present study, we have explored the possible role of mesenchymal stem cells (MSCs) in regulating the paclitaxel-sensitivity of ErbB2/ErbB3-coexpressing breast cancer cells. We show that human umbilical cord-derived MSCs express significantly higher level of neuregulin-1 as compared with ErbB2/ErbB3-coexpressing breast cancer cells themselves. Coculture or treatment with conditioned medium of MSCs not only decreases the anti-proliferation effect of paclitaxel on ErbB2/ErbB3-coexpressing breast cancer cells, but also significantly inhibits paclitaxel-induced apoptosis. We further demonstrate that this MSCs-drived paclitaxel resistance in ErbB2/ErbB3-coexpressing breast cancer cells could be attributed to upregulation of Survivin via paracrine effect of NRG-1/ErbB3/PI-3K/Akt signaling, as either specific knockdown expression of ErbB3, or blocking of downstream PI-3K/Akt signaling, or specific inhibition of Survivin can completely reverse this effect. Moreover, targeted knockdown of NRG-1 expression in MSCs abrogates theirs effect on paclitaxel sensitivity of ErbB2/ErbB3-coexpressing breast cancer cells. Taken together, our study indicate that paracrine of NRG-1 by MSCs induces paclitaxel resistance in ErbB2/ErbB3-coexpressing breast cancer cells through PI-3K/Akt signaling-dependent upregulation of Survivin. Our findings suggest that simultaneously targeting mesenchymal stem cells in tumor microenvironment may be a novel strategy to overcome paclitaxel resistance in patients with ErbB2/ErbB3-coexpressing breast cancer.

MicroRNA-mediated epigenetic targeting of Survivin significantly enhances the antitumor activity of paclitaxel against non-small cell lung cancer.

Elevated expression of Survivin correlates with poor prognosis, tumor recurrence, and drug resistance in various human cancers, including non-small cell lung cancer (NSCLC). The underlying mechanism of Survivin upregulation in cancer cells remains elusive. To date, no Survivin-targeted therapy has been approved for cancer treatment. Here, we explored the molecular basis resulting in Survivin overexpression in NSCLC and investigated the antitumor activity of the class I HDAC inhibitor entinostat in combination with paclitaxel. Our data showed that entinostat significantly enhanced paclitaxel-mediated anti-proliferative/anti-survival effects on NSCLC cells in vitro and in vivo. Mechanistically, entinostat selectively decreased expression of Survivin via induction of miR-203 (in vitro and in vivo) and miR-542-3p (in vitro). Moreover, analysis of NSCLC patient samples revealed that the expression levels of miR-203 were downregulated due to promoter hypermethylation in 45% of NSCLC tumors. In contrast, increased expression of both DNA methytransferase I (DNMT1) and Survivin was observed and significantly correlated with the reduced miR-203 in NSCLC. Collectively, these data shed new lights on the molecular mechanism of Survivin upregulation in NSCLC. Our findings also support that the combinatorial treatments of entinostat and paclitaxel will likely exhibit survival benefit in the NSCLC patients with overexpression of DNMT1 and/or Survivin. The DNMT1-miR-203-Survivin signaling axis may provide a new avenue for the development of novel epigenetic approaches to enhance the chemotherapeutic efficacy against NSCLC.