Identification and Fungicide Sensitivity of Fusarium spp. Associated with Root Rot of Scutellaria baicalensis in Shanxi Province, China.

Fusarium root rot is usually classified as an extremely destructive soilborne disease. From 2020 to 2021, Fusarium root rot was observed in production areas and seriously affected the yield and quality of Scutellaria baicalensis in Shanxi Province, China. Based on morphological characteristics and combined analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-alpha sequences, 68 Fusarium isolates obtained in this work were identified as F. oxysporum (52.94%), F. acuminatum (20.59%), F. solani (16.17%), F. proliferatum (5.88%), F. incarnatum (2.94%), and F. brachygibbosum (1.47%). In the pathogenicity tests, all Fusarium isolates could infect S. baicalensis roots, presenting different pathogenic ability. Among these isolates, F. oxysporum was found to have the highest virulence on S. baicalensis roots, followed by F. acuminatum, F. solani, F. proliferatum, F. brachygibbosum, and F. incarnatum. According to fungicide sensitivity tests, Fusarium isolates were more sensitive to fludioxonil and difenoconazole, followed by carbendazim, thiophanate-methyl, and hymexazol. In brief, this is the first report of Fusarium species (F. oxysporum, F. acuminatum, F. solani, F. proliferatum, F. incarnatum, and F. brachygibbosum) as causal agents of root rot of S. baicalensis in Shanxi Province, China. The fungicide sensitivity results will be helpful for formulating management strategies of S. baicalensis root rot.

Isolation, identification and transcriptome analysis of triadimefon-degrading strain Enterobacter hormaechei TY18.

Triadimefon, a type of triazole systemic fungicide, has been extensively used to control various fungal diseases. However, triadimefon could lead to severe environmental pollution, and even threatens human health. To eliminate triadimefon residues, a triadimefon-degrading bacterial strain TY18 was isolated from a long-term polluted site and was identified as Enterobacter hormaechei. Strain TY18 could grow well in a carbon salt medium with triadimefon as the sole nitrogen source, and could efficiently degrade triadimefon. Under triadimefon stress, a total of 430 differentially expressed genes (DEGs), including 197 up-regulated and 233 down-regulated DEGs, were identified in strain TY18 using transcriptome sequencing (RNA-Seq). Functional classification and enrichment analysis revealed that these DEGs were mainly related to amino acid transport and metabolism, carbohydrate transport and metabolism, small molecule and pyrimidine metabolism. Interestingly, the DEGs encoding monooxygenase and hydrolase activity acting on carbon-nitrogen were highly up-regulated, might be mainly responsible for the metabolism in triadimefon. Our findings in this work suggest that strain E. hormaechei TY18 could efficiently degrade triadimefon for the first time. They provide a great potential to manage triadimefon biodegradation in the environment successfully.

Small-sample continual learning classification method with vaccine to update memory cells based on the artificial immune system.

In this paper, a novel continual learning classification method (SCLM) in small sample cases is proposed, which inspired by the immune system's continuous improvement of immunity through injecting vaccines. Data-driven classification method requires a large number of historical data to establish a pattern recognition model with good generalization performance. However, in practice, the data that can be used for training is usually small and unbalanced, which lead to poor classification accuracy. In addition, batch learning method cannot improve continually classification performance by learning test phase data. In view of the above problems, SCLM generates sample as vaccine by finding the group center of training samples, so that B cells mature and activate memory cells in the train phase. In the test phase, the recognition ability of SCLM is further improved by learning new samples and updating memory cells. In order to evaluate its performance under the condition of less training samples and its possible advantages, the experiments on well-known datasets in UCI repository and reciprocating compressor faults diagnose were performed. The results show that SCLM has better classification performance than other methods when the number of training samples is insufficient. At the same time, the method of generating data has significantly improved the classification performance of other methods.

ZSTK474 Sensitizes Glioblastoma to Temozolomide by Blocking Homologous Recombination Repair.

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) is used as the standard chemotherapeutic agent for GBM but with limited success, and treatment failure is mainly due to tumor resistance. One of the leading causes of TMZ resistance is the upregulation of the DNA repair mechanism. Therefore, targeting the DNA damage response (DDR) is proposed to be an effective strategy to sensitize tumor cells to TMZ. In the present study, we demonstrated that the combined use of the PI3K inhibitor ZSTK474 and TMZ showed synergetic anticancer effects on human GBM cells in vitro and in vivo. The combination treatment led to significantly increased cell apoptosis and DNA double strand breaks (DSBs). In addition, a mechanistic study indicated that TMZ enhanced the homologous recombination (HR) repair efficiency in GBM cells, while ZSTK474 impaired HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51, thereby sensitizing GBM cells to TMZ. Moreover, TMZ activated the PI3K signaling pathway through upregulation of the PI3K catalytic subunits p110α and p110ß and the phosphorylation of Akt. Meanwhile, ZSTK474 blocked the activity of the PI3K/Akt pathway. Taken together, our findings suggested that the combination of ZSTK474 and TMZ might be a potential therapeutic option for GBM.

Palmitic acid inhibits prostate cancer cell proliferation and metastasis by suppressing the PI3K/Akt pathway.

AIMS: Prostate cancer is one of the most frequent causes of cancer death in men worldwide, and novel drugs for prostate cancer therapies are still being developed. Palmitic acid is a common saturated long-chain fatty acid that is known to exhibit anti-inflammatory and metabolic regulatory effects and antitumor activities in several types of tumors. The present study aims to explore the antiproliferative and antimetastatic activities of palmitic acid on human prostate cancer cells and the underlying mechanism. MAIN METHODS: MTT and colony formation assays were utilized to determine the antiproliferative effect of palmitic acid. Cell metastasis was evaluated by wound healing, Transwell migration and invasion assay. The in vivo anticancer effect was assessed by a nude mouse xenograft model of prostate cancer. The involved molecular mechanisms were investigated by flow cytometry and Western blot analysis. KEY FINDINGS: Palmitic acid significantly suppressed prostate cancer cell growth in vitro and in vivo. Treatment with palmitic acid induced G1 phase arrest, which was associated with downregulation of cyclin D1 and p-Rb and upregulation of p27. In addition, palmitic acid could inhibit prostate cancer cell metastasis, in which suppression of PKCζ and p-Integrinß1 and an increase in E-cadherin expression might be involved. Furthermore, a mechanistic study indicated that palmitic acid inhibited the key molecules of the PI3K/Akt pathway to block prostate cancer proliferation and metastasis. SIGNIFICANCE: Our findings suggested the antitumor potential of palmitic acid for prostate cancer by targeting the PI3K/Akt pathway.

STAT3 Inhibitor Napabucasin Inhibits Tumor Growth and Cooperates with Proteasome Inhibition in Human Ovarian Cancer Cells.

BACKGROUND: Ovarian cancer is a disease with the highest mortality in gynecologic malignancies. Activation of STAT3 pathway is well known to be associated with tumor progression and metastasis in a number of cancers, including ovarian cancer. Therefore, STAT3 may be an ideal target for ovarian cancer treatment. OBJECTIVE: The present study aims to determine the antitumor activity of STAT3 inhibitor Napabucasin as a single agent or in combination with proteasome inhibitor MG-132 in ovarian cancer cells. METHODS: MTT was performed to determine the anti-proliferative effect of Napabucasin on ovarian cancer SKOV-3 cells. The involved anti-tumor mechanism was explored by flow cytometry, qRTPCR and western blot. MDC staining and tandem mRFP-GFP-LC3 fluorescence microscopy were used to analyze the autophagy-inducing capability of Napabucasin with or without MG-132. The combinational anticancer effect of Napabucasin and MG-132 was evaluated according to Chou and Talalay's method (1984). RESULTS: Napabucasin showed obvious tumor-inhibitory effects against SKOV-3 cells. Treatment by Napabucasin arrested cell cycle progression in G2/M phase. Mechanistically, elevated expression of p21 may contribute to the blockade of the cell cycle. Moreover, we demonstrated that Napabucasin induced autophagy in SKOV-3 cells by using various assays, including MDC staining, autophagic flux examination, and detection of the autophagy markers. In addition, a combination of Napabucaisin with MG-132 exhibited a significant synergistic anti-proliferative effect, probably by inducing apoptosis through a mitochondria-dependent pathway. The two compounds induced pro-survival autophagies, and co-treatment with autophagy inhibiter might further enhance their antitumor effects. CONCLUSION: Napabucasin alone or in combination with MG-132 might be promising treatment strategy for ovarian cancer patients.

Hydroxychloroquine synergizes with the PI3K inhibitor BKM120 to exhibit antitumor efficacy independent of autophagy.

BACKGROUND: The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer. METHODS: The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining. RESULTS: HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51. CONCLUSIONS: Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the "off target" effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.

Co-targeting PI3K/Akt and MAPK/ERK pathways leads to an enhanced antitumor effect on human hypopharyngeal squamous cell carcinoma.

PURPOSE: The present study aims to determine whether co-targeting PI3K/Akt and MAPK/ERK pathways in human hypopharyngeal squamous cell carcinoma (HSCC) is a potential anticancer strategy. METHODS: We retrospectively analyzed the clinical data of HSCC patients, and the phosphorylation status of Akt and Erk in HSCC and tumor adjacent tissues was evaluated by immunohistochemistry. MTT and colony formation assay were performed to determine the anti-proliferative effect of PI3K/mTOR inhibitor GDC-0980 and MEK inhibitor Refametinib on HSCC cell line Fadu. Wound-healing and Transwell migration assay were used to analyze the anti-migrative capability of the two drugs. The involved anti-tumor mechanism was explored by flow cytometry, qRT-PCR and western blot. The combinational anticancer effect of GDC-0980 and Refametinib was evaluated according to Chou and Talalay's method. RESULTS: The levels of p-Akt and p-Erk were increased significantly with the progression of clinical stage of HSCC, suggesting PI3K/Akt and MAPK/ERK pathways might be associated with HSCC occurrence and progression. Furthermore, both GDC-0980 and Refametinib showed obvious antitumor effects on FaDu cells. Treatment by the two drugs arrested FaDu cell cycle progression in G1 phase, with reduction of cyclin D1 and p-Rb, in contrast to enhancement of p27. GDC-0980 inhibited FaDu cell migration and reduced metastasis related proteins including p-PKCζ, p-Integrin ß1 and uPA. Combination use of GDC-0980 and Refametinib exhibited strong synergistic anti-tumor effect. CONCLUSION: Dual inhibition of PI3K/Akt and MAPK/ERK pathway by GDC-0980 and Refametinib might be a promising treatment strategy for HSCC patients.