Periplocin suppresses the growth of colorectal cancer cells by triggering LGALS3 (galectin 3)-mediated lysophagy.

Colorectal cancer (CRC) is one of the most common malignancies worldwide and remains a major clinical challenge. Periplocin, a major bioactive component of the traditional Chinese herb Cortex periplocae, has recently been reported to be a potential anticancer drug. However, the mechanism of action is poorly understood. Here, we show that periplocin exhibits promising anticancer activity against CRC both in vitro and in vivo. Mechanistically, periplocin promotes lysosomal damage and induces apoptosis in CRC cells. Notably, periplocin upregulates LGALS3 (galectin 3) by binding and preventing LGALS3 from Lys210 ubiquitination-mediated proteasomal degradation, leading to the induction of excessive lysophagy and resultant exacerbation of lysosomal damage. Inhibition of LGALS3-mediated lysophagy attenuates periplocin-induced lysosomal damage and growth inhibition in CRC cells, suggesting a critical role of lysophagy in the anticancer effects of periplocin. Taken together, our results reveal a novel link between periplocin and the lysophagy machinery, and indicate periplocin as a potential therapeutic option for the treatment of CRC.Abbreviations: 3-MA: 3-methyladenine; ACACA/ACC1: acetyl-CoA carboxylase alpha; AMPK: adenosine monophosphate-activated protein kinase; AO: Acridine orange; ATG5: autophagy related 5; ATG7: autophagy related 7; CALM: calmodulin; CHX: cycloheximide; CRC: colorectal cancer; CQ: chloroquine; CTSB: cathepsin B; CTSD: cathepsin D; ESCRT: endosomal sorting complex required for transport; LAMP1: lysosomal associated membrane protein 1; LMP: lysosomal membrane permeabilization; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCOLN1/TRPML1: mucolipin TRP cation channel 1; MKI67/Ki-67: marker of proliferation Ki-67; MTOR: mechanistic target of rapamycin kinase; P2RX4/P2X4: purinergic receptor P2X 4; PARP1/PARP: poly(ADP-ribose) polymerase 1; PRKAA/AMPKα: protein kinase AMP-activated catalytic subunit alpha; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TRIM16: tripartite motif containing 16.

PHGDH arginine methylation by PRMT1 promotes serine synthesis and represents a therapeutic vulnerability in hepatocellular carcinoma.

Serine synthesis is crucial for tumor growth and survival, but its regulatory mechanism in cancer remains elusive. Here, using integrative metabolomics and transcriptomics analyses, we show a heterogeneity between metabolite and transcript profiles. Specifically, the level of serine in hepatocellular carcinoma (HCC) tissues is increased, whereas the expression of phosphoglycerate dehydrogenase (PHGDH), the first rate-limiting enzyme in serine biosynthesis pathway, is markedly downregulated. Interestingly, the increased serine level is obtained by enhanced PHGDH catalytic activity due to protein arginine methyltransferase 1 (PRMT1)-mediated methylation of PHGDH at arginine 236. PRMT1-mediated PHGDH methylation and activation potentiates serine synthesis, ameliorates oxidative stress, and promotes HCC growth in vitro and in vivo. Furthermore, PRMT1-mediated PHGDH methylation correlates with PHGDH hyperactivation and serine accumulation in human HCC tissues, and is predictive of poor prognosis of HCC patients. Notably, blocking PHGDH methylation with a TAT-tagged nonmethylated peptide inhibits serine synthesis and restrains HCC growth in an HCC patient-derived xenograft (PDX) model and subcutaneous HCC cell-derived xenograft model. Overall, our findings reveal a regulatory mechanism of PHGDH activity and serine synthesis, and suggest PHGDH methylation as a potential therapeutic vulnerability in HCC.

PHLDB2 Mediates Cetuximab Resistance via Interacting With EGFR in Latent Metastasis of Colorectal Cancer.

BACKGROUND & AIMS: Latent metastasis of colorectal cancer (CRC) frequently develops months or years after primary surgery, followed by adjuvant therapies, and may progress rapidly even with targeted therapy administered, but the underlying mechanism remains unclear. Here, we aim to explore the molecular basis for the aggressive behavior of latent metastasis in CRC. METHODS: Transcriptional profiling and pathway enrichment analysis of paired primary and metastatic tumor samples were performed. The underlying mechanisms of pleckstrin homology-like domain, family B, member 2 (PHLDB2) in CRC were investigated by RNA immunoprecipitation assay, immunohistochemistry, mass spectrometry analysis, and Duolink in situ proximity ligation assay (Sigma-Aldrich, Shanghai, China). The efficacy of targeting PHLDB2 in cetuximab treatment was elucidated in CRC cell lines and mouse models. RESULTS: Based on the transcriptional profile of paired primary and metastatic tumor samples, we identified PHLDB2 as a potential regulator in latent liver metastasis. A detailed mechanistic study showed that chemotherapeutic agent-induced oxidative stress promotes methyltransferase-like 14 (METTL14)-mediated N6-methyladenosine modification of PHLDB2 messenger RNA, facilitating its protein expression. Up-regulated PHLDB2 stabilizes epidermal growth factor receptor (EGFR) and promotes its nuclear translocation, which in turn results in EGFR signaling activation and consequent cetuximab resistance. Moreover, Arg1163 (R1163) of PHLDB2 is crucial for interaction with EGFR, and the R1163A mutation abrogates its regulatory function in EGFR signaling. CONCLUSIONS: PHLDB2 plays a crucial role in cetuximab resistance and is proposed to be a potential target for the treatment of CRC.

MCT1 relieves osimertinib-induced CRC suppression by promoting autophagy through the LKB1/AMPK signaling.

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. Development of novel chemotherapeutics is still required to enable successful treatment and improve survival for CRC patients. Here, we found that osimertinib (OSI) exhibits potent anti-CRC effects by inducing apoptosis, independent of its selective inhibitory activity targeting the EGFR T790M mutation. Intriguingly, OSI treatment triggers autophagic flux in CRC cells. Inhibition of autophagy markedly augments OSI-induced apoptosis and growth inhibition in CRC cells, suggesting a protective role of autophagy in response to OSI treatment. Mechanistically, OSI upregulates the expression of monocarboxylate transporter 1 (MCT1) and subsequently activates LKB1/AMPK signaling, leading to autophagy induction in CRC cells. Notably, OSI significantly exaggerates the sensitivity of CRC cells to the first-line drugs 5-fluorouracil or oxaliplatin. Taken together, our study unravels a novel mechanism of OSI-mediated protective autophagy involving MCT1/LKB1/AMPK signaling, and suggests the use of OSI as a potential agent for clinical CRC treatment.

Tubeimoside I induces accumulation of impaired autophagolysosome against cervical cancer cells by both initiating autophagy and inhibiting lysosomal function.

Cervical cancer is one of the most aggressive human cancers with poor prognosis due to constant chemoresistance and repeated relapse. Tubeimoside I (TBM) has been identified as a potent antitumor agent that inhibits cancer cell proliferation by triggering apoptosis and inducing cell cycle arrest. Nevertheless, the detailed mechanism remains unclear and needs to be further elucidated, especially in cervical cancer. In this study, we found that TBM could induce proliferation inhibition and cell death in cervical cancer cells both in vitro and in vivo. Further results demonstrated that treatment with TBM could induce autophagosome accumulation, which was important to TBM against cervical cancer cells. Mechanism studies showed that TBM increased autophagosome by two pathways: First, TBM could initiate autophagy by activating AMPK that would lead to stabilization of the Beclin1-Vps34 complex via dissociating Bcl-2 from Beclin1; Second, TBM could impair lysosomal cathepsin activity and block autophagic flux, leading to accumulation of impaired autophagolysosomes. In line with this, inhibition of autophagy initiation attenuated TBM-induced cell death, whereas autophagic flux inhibition could exacerbated the cytotoxic activity of TBM in cervical cancer cells. Strikingly, as a novel lethal impaired autophagolysosome inducer, TBM might enhance the therapeutic effects of chemotherapeutic drugs towards cervical cancer, such as cisplatin and paclitaxel. Together, our study provides new insights into the molecular mechanisms of TBM in the antitumor therapy, and establishes potential applications of TBM for cervical cancer treatment in clinic.

[Relationship Between the Vegetation Community and Soil Nutrient and Enzyme Activity During the Restoration of Abandoned Land in the Loess Hilly Region].

The trends of and relationships among the plant community, soil nutrients, and four soil enzymes were investigated after being abandoned for 10, 15, 20, 30, and 45 years to reveal the soil properties during the restoration in the Loess Hilly Region. The results indicate the following ranking of dominant plant community species:Artemisia scoparia→Lespedeza dahurica+Artemisia sacrorum→Artemisia giraldii+irons Artemisia annua→Bothriochloa flaccidum+Artemisia selengensis. The ranking reflects an increase along the chronosequence of abandoned land. Moreover, the ratio of the total species of Compositae, Poaceae, and Leguminosae decreases from 66.67% to 50% and then increases up to 75%. The SOC, TN, TP, AN, AP, and four enzyme activity types (ALP, CAT, UE, and SC) increase but respond differently to restoration, while the stoichiometric ratio fluctuates. In contrast to the number of plant families, genus, species, and plant diversity, Compositae, Poaceae, and Leguminosae have major effects on the soil nutrient and enzyme activity, which explains the total variation of 72.8%, 69.1%, and 66.0%, respectively. The effects of these three families on the soil enzymes are greater than that on soil nutrients. Poaceae and Leguminosae have a positive effect on the nutrient and enzyme activity, while the family Compositae has a negative effect. Overall, the changes of dominant species of grassland communities during restoration significantly affect the soil enzyme and thereby are responsible for the soil nutrient dynamics.

Proteogenomic studies on cancer drug resistance: towards biomarker discovery and target identification.

INTRODUCTION: Chemoresistance is a major obstacle for current cancer treatment. Proteogenomics is a powerful multi-omics research field that uses customized protein sequence databases generated by genomic and transcriptomic information to identify novel genes (e.g. noncoding, mutation and fusion genes) from mass spectrometry-based proteomic data. By identifying aberrations that are differentially expressed between tumor and normal pairs, this approach can also be applied to validate protein variants in cancer, which may reveal the response to drug treatment. Areas covered: In this review, we will present recent advances in proteogenomic investigations of cancer drug resistance with an emphasis on integrative proteogenomic pipelines and the biomarker discovery which contributes to achieving the goal of using precision/personalized medicine for cancer treatment. Expert commentary: The discovery and comprehensive understanding of potential biomarkers help identify the cohort of patients who may benefit from particular treatments, and will assist real-time clinical decision-making to maximize therapeutic efficacy and minimize adverse effects. With the development of MS-based proteomics and NGS-based sequencing, a growing number of proteogenomic tools are being developed specifically to investigate cancer drug resistance.

A rapid Raman detection of deoxynivalenol in agricultural products.

Mycotoxin results in financial damage and considerable safety risks. In this paper, the possibility of portable Raman system-based surface-enhanced Raman scattering (SERS) for a rapid detection of deoxynivalenol (DON) a mycotoxin in cereals was investigated. Under an optimized condition, SERS analysis for pure DON solution has a wide dynamic concentration range from 10-7M to 10-2M with the limit of detection (LOD) down to 100nM. Density functional theory (DFT) analysis at the level of B3LYP/6-311++G(d, p) was also preformed for vibrational assignment. For practical application, the LOD of the proposed Raman method for both DON-contaminated corns and kidney beans were validated as 10-6M and the LOD for DON-contaminated oats was 10-4M. As a perspective, the SERS-based technology could be developed into an alternatively promising assay for on-field detection of DON residues at various cereals due to it high sensitivity and selectivity.

Optimized core-shell Au@Ag nanoparticles for label-free Raman determination of trace Rhodamine B with cancer risk in food product.

A simple and reliable method based on surface-enhanced Raman scattering (SERS) with a portable Raman system is described for sensitive determination of trace levels of Rhodamine B (RB) in hot sauce samples. The sodium salt of phytic acid (IP6) stabilized Au@Ag core-shell bimetallic nanoparticles are constructed and used as SERS substrate, yielding high Raman enhancement of RB. The limit of detection for RB in water is 5 nM (2 ppb), which is below China Exit and Entry Inspection and Quarantine Bureau's tolerance level of 5 ppb. Also, the proposed easy assay of IP6-Au@Ag NPs combining with portable Raman system could be applied for on-site monitoring RB in hot sauce.

Magnetically optimized SERS assay for rapid detection of trace drug-related biomarkers in saliva and fingerprints.

New developments in the fields of human healthcare and social security call for the exploration of an easy and on-field method to detect drug-related biomarkers. In this paper, Au nanoparticles dotted magnetic nanocomposites (AMN) modified with inositol hexakisphosphate (IP6) were used as surface-enhanced Raman scattering (SERS) substrate to quickly monitor trace drug-related biomarkers in saliva and to on-site screen a trace drug biomarker in fingerprints. Due to inducing with an external magnet, such substrate presented a huge SERS activity, which has met the sensitivity requirement for assay to detect the drug biomarkers in saliva from the U.S. Substance Abuse and Mental Health Services Administration, and also the limit of detection for drug biomarker in fingerprint reached 100 nM. In addition, this AMN-based SERS assay was successfully conducted using a portable Raman spectrometer, which could be used to on-site and accurately differentiate between the smokers and drug addicts in near future.

Facile and label-free detection of lung cancer biomarker in urine by magnetically assisted surface-enhanced Raman scattering.

Adenosine plays a crucial role in the regulation of physiological activity in various tissues and organs. As adenosine is a possible biomarker for cancer, the determination of its level presents a demanding task for deeply monitoring progress of diseases. Through the synthesis of Fe3O4/Au/Ag nanocomposites weaved and stabilized by phytic acid and its salt, we develop a magnetically assisted surface-enhanced Raman scattering (SERS) protocol to determine trace level adenosine in urine samples from both lung cancer patients and health human. The magnetic properties of the nanocomposites enable to realize the simple separation of targeted molecules from a complex matrix and the Au/Ag nanoparticles moieties act as the SERS platform. This label-free Fe3O4/Au/Ag-nanocomposites-based SERS protocol shows a good stability, reproducibility, time efficiency (less than 20 min for one sample test), and huge sensitivity down to 1 × 10(-10) M. The protocol also has high selectivity because SERS signal of adenosine provides the molecular fingerprint information as well as an azo coupling pretreatment is performed to remove the interference of urea. Furthermore, a SERS array is designed for on-site screening adenosine in urine samples in a massive way using a portable Raman. Such a magnetically assisted SERS method as a powerful alternative can be expected as a smart and promising tool for effective assessment of healthcare.

Improving SERS activity of inositol hexaphosphate capped silver nanoparticles: Fe3+ as a switcher.

Inositol hexaphosphate (IP6) capped silver nanoparticles (IP6@AgNPs) were fabricated as surface-enhanced Raman scattering (SERS) active substrates. SERS activity of IP6@AgNPs could be further improved via adding due amounts of Fe(3+) to form Fe(3+)-IP6@AgNPs. The mechanism of Fe(3+)-induced SERS improvement of IP6@AgNPs can be attributed to the strong interaction of IP6 and Fe(3+), which leads to controllable adjustment of the gap among neighboring nanoparticles to produce "hot spots". The above mechanism was confirmed with ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Such Fe(3+)-IP6@AgNPs-based SERS system was used to detect Rhodamine 6G (R6G) down to the trace level of 10(-10) mol L(-1). Besides, New Fuchsin (NF) was also used as a Raman probe to calculate the enhancement factor (EF) of IP6@AgNPs without and with Fe(3+). The SERS activity of IP6@AgNPs happened extreme decrease after one-year storage and could be recovered to great extent aided by the addition of Fe(3+). The Fe(3+) optimized IP6@AgNPs system could be applied to detect thymine at trace level by SERS.

Au dotted magnetic network nanostructure and its application for on-site monitoring femtomolar level pesticide.

A novel magnetically responsive and surface-enhanced Raman spectroscopy (SERS) active nanocomposite is designed and prepared by direct grafting of Au nanoparticles onto the surface of magnetic network nanostructure (MNN) with the help of a nontoxic and environmentally friendly reagent of inositol hexakisphosphate shortly named as IP6. The presence of IP6 as a stabilizer and a bridging agent could weave Fe3O4 nanoparticles (NPs) into magnetic network nanostructure, which is easily dotted with Au nanoparticles (Au NPs). It has been shown firstly that the huge Raman enhancement of Au-MNN is reached by an external magnetic collection. Au-MNN presenting the large surface and high detection sensitivity enables it to exhibit multifunctional applications involving sufficient adsorption of dissolved chemical species for enrichment, separation, as well as a Raman amplifier for the analysis of trace pesticide residues at femtomolar level by a portable Raman spectrometer. Therefore, such multifunctional nanocomposites can be developed as a smart and promising nanosystem that integrates SERS approach with an easy assay for concentration by an external magnet for the effective on-site assessments of agricultural and environmental safety.