Engineering of Cas12a nuclease variants with enhanced genome-editing specificity.

The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas12a system is a powerful tool in gene editing; however, crRNA-DNA mismatches might induce unwanted cleavage events, especially at the distal end of the PAM. To minimize this limitation, we engineered a hyper fidelity AsCas12a variant carrying the mutations S186A/R301A/T315A/Q1014A/K414A (termed HyperFi-As) by modifying amino acid residues interacting with the target DNA and crRNA strand. HyperFi-As retains on-target activities comparable to wild-type AsCas12a (AsCas12aWT) in human cells. We demonstrated that HyperFi-As has dramatically reduced off-target effects in human cells, and HyperFi-As possessed notably a lower tolerance to mismatch at the position of the PAM-distal region compared with the wild type. Further, a modified single-molecule DNA unzipping assay at proper constant force was applied to evaluate the stability and transient stages of the CRISPR/Cas ribonucleoprotein (RNP) complex. Multiple states were sensitively detected during the disassembly of the DNA-Cas12a-crRNA complexes. On off-target DNA substrates, the HyperFi-As-crRNA was harder to maintain the R-loop complex state compared to the AsCas12aWT, which could explain exactly why the HyperFi-As has low off-targeting effects in human cells. Our findings provide a novel version of AsCas12a variant with low off-target effects, especially capable of dealing with the high off-targeting in the distal region from the PAM. An insight into how the AsCas12a variant behaves at off-target sites was also revealed at the single-molecule level and the unzipping assay to evaluate multiple states of CRISPR/Cas RNP complexes might be greatly helpful for a deep understanding of how CRISPR/Cas behaves and how to engineer it in future.

Engineering of a compact, high-fidelity EbCas12a variant that can be packaged with its crRNA into an all-in-one AAV vector delivery system.

The CRISPR-associated endonuclease Cas12a has become a powerful genome-editing tool in biomedical research due to its ease of use and low off-targeting. However, the size of Cas12a severely limits clinical applications such as adeno-associated virus (AAV)-based gene therapy. Here, we characterized a novel compact Cas12a ortholog, termed EbCas12a, from the metagenome-assembled genome of a currently unclassified Erysipelotrichia. It has the PAM sequence of 5'-TTTV-3' (V = A, G, C) and the smallest size of approximately 3.47 kb among the Cas12a orthologs reported so far. In addition, enhanced EbCas12a (enEbCas12a) was also designed to have comparable editing efficiency with higher specificity to AsCas12a and LbCas12a in mammalian cells at multiple target sites. Based on the compact enEbCas12a, an all-in-one AAV delivery system with crRNA for Cas12a was developed for both in vitro and in vivo applications. Overall, the novel smallest high-fidelity enEbCas12a, this first case of the all-in-one AAV delivery for Cas12a could greatly boost future gene therapy and scientific research.

Seismic constraints and geodynamic implications of differential lithosphere-asthenosphere flow revealed in East Asia.

During the last 50 Ma, the East Asian continent has been a zone of massive continental collision and lithospheric deformation. While the consequences of this for Asian surface and lithospheric deformation have been intensively studied over the past 4 decades, the relationships between lithospheric deformation and underlying asthenospheric flow have been more difficult to constrain. Here we present a high resolution 3-D azimuthal anisotropy model for the northeastern Tibetan Plateau and its eastward continuation based on surface-wave tomography and shear-wave splitting measurements. This model shows that eastward lateral flow of asthenosphere beneath the northeastern Tibetan Plateau is being blocked by thick Ordos and Sichuan cratonic keels. The damming effect of these keels induces flow to first rotate around the Ordos keel and then transition into strong east-west flow beneath the thinner lithosphere that forms the lithospheric suture between the two cratonic keels. We further find that asthenosphere flow directions can differ from those of overlying lithosphere, with the asthenosphere neither being passively dragged by overlying lithosphere, nor being able to drag the overlying plate to mimic its subsurface flow. Finally, the region of eastward-channeled asthenospheric flow from Tibet underlies a belt of stronger intracontinental deformation in eastern China.

Decoding the transcriptional heterogeneity, differentiation lineage, clinical significance in tissue-resident memory CD8 T cell of the small intestine by single-cell analysis.

Resident memory T (Trm) cells which are specifically located in non-lymphoid tissues showed distinct phenotypes and functions compared to circulating memory T cells and were vital for the initiation of robust immune response within tissues. However, the heterogeneity in the transcriptional features, development pathways, and cancer response of Trm cells in the small intestine was not demonstrated. Here, we integrated scRNA-seq and scTCR-seq data pan-tissue T cells to explore the heterogeneity of Trm cells and their development pathways. Trm were enriched in tissue-specific immune response and those in the DUO specially interacted with B cells via TNF and MHC-I signatures. T cell lineage analyses demonstrated that Trm might be derived from the T_CD4/CD8 subset within the same organ or migrated from spleen and mesenteric lymph nodes. We compared the immune repertoire of Trm among organs and implied that clonotypes in both DUO and ILE were less expanded and hydrophilic TRB CDR3s were enriched in the DUO. We further demonstrated that Trm in the intestine infiltrated the colorectal cancer and several effector molecules were highly expressed. Finally, the TCGA dataset of colorectal cancer implied that the infiltration of Trm from the DUO and the ILE was beneficial for overall survival and the response to immune checkpoint blockade.

A Comparison of Clinicopathologic Outcomes and Patterns of Lymphatic Spread Across Neoadjuvant Chemotherapy, Neoadjuvant Chemoradiotherapy, and Neoadjuvant Immunochemotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma.

BACKGROUND: Neoadjuvant chemoradiotherapy (NCRT) is recommended as the treatment standard for locally advanced esophageal squamous cell carcinoma (ESCC). The use of immunotherapy in the neoadjuvant setting has gained attention. Multiple, clinical trials have explored the efficacy and safety of neoadjuvant immunochemotherapy (NICT). We evaluated the differences in clinicopathologic outcomes and the patterns of lymphatic spread among patients receiving neoadjuvant chemotherapy (NCT), NCRT, and NICT before esophagectomy for locally advanced ESCC. METHODS: A total of 702 patients with ESCC who completed transthoracic esophagectomy followed neoadjuvant therapy were included. Pathological characteristics, including pathologic complete response (pCR), tumor regression grade (TRG) score and patterns of lymphatic spread, were evaluated. RESULTS: Compared with the NCT group, the NCRT group and NICT group had an advantage in pathological response (P < 0.05). The pCR rate was 8.1% in the NCT group, 29.9% in the NCRT group, and 23.6% in the NICT group. The TRG score (P < 0.05) and pathologic T stage (P < 0.05) in the NCT group were significantly higher. Compared with NICT, NCRT can significantly reduce the rate of lymph node metastasis rate in station 1R (0 vs. 3.4%, P < 0.05) and 2R (1.1% vs. 6.8%, P < 0.05). Subgroup analysis according to the tumor location distribution showed that NICT group had higher lymph node metastasis rate in station 2R (9.1%) in middle thoracic cases (P < 0.05) and in station 18 (7.5%) (P < 0.05) in lower thoracic cases. CONCLUSIONS: NCRT or NICT followed by surgery may result in a promising pCR rate and show a better performance in therapeutic response of primary lesion. For patients with lymph node metastasis in station 1R and 2R, NCRT should be the optimal preoperative treatment strategy.

Activating receptor KIR2DS2 bound to HLA-C1 reveals the novel recognition features of activating receptor.

Killer cell immunoglobulin-like receptors (KIRs) are important receptors for regulating the killing of virus-infected or cancer cells of natural killer (NK) cells. KIR2DS2 can recognize peptides derived from hepatitis C virus (HCV) or global flaviviruses (such as dengue and Zika) presented by HLA-C*0102 to activate NK cells, and has shown promising results when used for cancer immunotherapy. Here, we present the complex structure of KIR2DS2 with HLA-C*0102 at a resolution of 2·5Å. Our structure reveals that KIR2DS2 can bind with HLA-C*0102 and HLA-A*1101 in two different directions. Moreover, Tyr45 (in activating receptor KIR2DS2) and Phe45 (in inhibitory KIRs) distinguish the two different binding models and binding affinity between activating KIRs and inhibitory KIRs. The conserved 'AT' motif of the peptide mediates recognition and determines the peptide specificity of recognition. These structural characteristics shed light on how KIRs activate NK cells and can provide a molecular basis for immunotherapy by NK cells.

LncRNA BBOX1-AS1 promotes pituitary adenoma progression via sponging miR-361-3p/E2F1 axis.

Pituitary adenoma is one of the most common intracranial tumors, more and more studies have shown that long non-coding RNA (lncRNA) plays a very important role in pituitary adenoma. However, there are few reports on the function of lncRNA BBOX1-AS1 in pituitary adenomas, and further exploration is needed. The objective of this research is to figure out what function BBOX1-AS1 plays in pituitary adenoma and how it regulates it. The expression of the E2F1, miR-361-3p and BOX1-AS1 genes was measured using a quantitative real-time PCR method. The functional involvement of BBOX1-AS1 in pituitary adenoma was examined utilizing the Transwell assay, western blot assays and the cell counting kit-8. RNA immunoprecipitation and luciferase reporter assays revealed that miR-361-3p binds to E2F1 or BBOX1-AS1. In addition, in-vivo assays were carried out. The expression of BBOX1-AS1 in pituitary adenoma tissues and cells has been increased, according to our findings. Furthermore, it is also noted that downregulation of BBOX1-AS1causes the inhibition of pituitary adenoma cells which result in invasion, apoptosis and proliferation, as well as boosting tumor development in vivo . In addition, BBOX1-AS1 knockdown inhibited tumor development in vivo . We identify BBOX1-AS1 bind to miR-361-3p and to suppress its expression in a negative way. Moreover, miR-361-3p has been shown to bind with E2F1 and inhibit its expression. E2F1 also corrected miR-361-3p-mediated cell invasion, proliferation and apoptosis in BBOX1-AS1-dysregulated pituitary adenoma cells in rescue tests. BBOX1-AS1 increases pituitary adenoma malignant activity by sponging miR-361-3p to upregulate E2F1 expression, which may lead to a new path in pituitary adenoma therapeutic attempts.

Dysfunction of apoptosis and autophagy correlates with local recurrence in esophageal squamous cell carcinoma after definitive chemoradiation.

OBJECTIVE: Definitive chemoradiotherapy (dCRT) is one of the standard treatments for esophageal squamous cell carcinoma (ESCC), but local recurrence is the main cause of treatment failure. The changes in apoptosis and autophagy in recurrent tumors of patients with ESCC following dCRT have been poorly estimated. Thus, this study aimed to investigate the expressions of key regulators of apoptosis and autophagy in matched paired samples of primary and recurrent ESCC. METHODS: The medical records of patients with locally advanced ESCC who developed local recurrence after dCRT were reviewed, and the expression profiling of apoptosis-related genes, cell apoptosis, autophagy and autophagy-related proteins were detected in normal esophageal squamous epithelium and paired samples of primary and recurrent ESCC. RESULTS: A total of 126 patients were enrolled, and 52.4% of them had stage III disease. The 1-, 3- and 5-year local recurrence-free survival (LRFS) rates were 54.8, 19.8 and 14.3%, respectively, with a median LRFS of 13.0 months. Patients with T2 tumor or stage II disease showed a significantly prolonged LRFS compared with that of patients with T3-4 tumor or stage III disease. The Apoptotic Machinery key genes expression profiling identified 5 upregulated and 7 downregulated apoptosis-related genes in recurrent tumors compared with their expression levels in the matched primary ESCC tumors. High expression of CD40, TRAF4 and BCL2A1, and low expression of CARD6 and TNFRSF21 were associated with increased risk of early local recurrence after dCRT. No differences in apoptotic index between primary and recurrent samples were detected. However, typical morphological features of autophagosomes and elevated LC3-II protein expression were detected in recurrent tumor samples, and positive LC3-II expression was correlated with increased risk of early local recurrence. CONCLUSION: Our findings indicated that apoptosis and autophagy dysfunction correlated with early local recurrence in patients with locally advanced ESCC receiving dCRT. Further studies are necessary to understand the biology of tumor recurrence in esophageal cancer.

First-line epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor alone or with whole-brain radiotherapy for brain metastases in patients with EGFR-mutated lung adenocarcinoma.

We proposed to compare the outcomes of first-line epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) alone with EGFR-TKI plus whole-brain radiotherapy (WBRT) for the treatment of brain metastases (BM) in patients with EGFR-mutated lung adenocarcinoma. A total of 1665 patients were screened from 2008 to 2014, and 132 were enrolled in our study. Among the 132 patients, 72 (54.5%) harbored a deletion in exon 19, 97 (73.5%) showed multiple intracranial lesions, and 67 (50.8%) had asymptomatic BM. Seventy-nine patients (59.8%) were treated with EGFR-TKI alone, 53 with concomitant WBRT. The intracranial objective response rate was significantly higher in the EGFR-TKI plus WBRT treatment group (67.9%) compared with the EGFR-TKI alone group (39.2%) (P = 0.001). After a median follow-up of 36.2 months, 62.1% of patients were still alive. The median intracranial TTP was 24.7 months (95% CI, 19.5-29.9) in patients who received WBRT, which was significantly longer than in those who received EGFR-TKI alone, with the median intracranial TTP of 18.2 months (95% CI, 12.5-23.9) (P = 0.004). There was no significant difference in overall survival between WBRT and EGFR-TKI alone groups, (median, 48.0 vs 41.1 months; P = 0.740). The overall survival is significantly prolonged in patients who had an intracranial TTP exceeding 22 months compared to those who developed intracranial progression <22 months after treatment, (median, 58.0 vs 28.0 months; P = 0.001). For EGFR-mutated lung adenocarcinoma patients with BM, treatment with concomitant WBRT achieved a higher response rate of BM and significant improvement in intracranial progression-free survival compared with EGFR-TKI alone.

Identification and differential expression analysis of MicroRNAs encoded by Tiger Frog Virus in cross-species infection in vitro.

BACKGROUND: Tiger frog virus (TFV), dsDNA virus of the genus Ranavirus and family Iridoviridae, causes a high mortality of tiger frog tadpoles cultured in Southern China. MicroRNAs (miRNAs) have been identified in many viruses especially DNA viruses such as Singapore Grouper Iridoviruses (SGIV). MicroRNAs play important roles in regulating gene expression for virus subsistence in host. Considering that TFV infects cells of different species under laboratory conditions, we aim to identify the specific and essential miRNAs expressed in ZF4 and HepG2 cells. METHODS: We identified and predicted novel viral miRNAs in TFV-infected ZF4 and HepG2 cells by deep sequencing and software prediction. Then, we verified and described the expression patterns of TFV-encoded miRNAs by using qRT-PCR and Northern blot. RESULTS: Deep sequencing predicted 24 novel TFV-encoded miRNAs, and qRT-PCR verified 19 and 23 miRNAs in TFV-infected ZF4 (Group Z) and HepG2 (Group H) cells, respectively. Northern blot was performed to validate eight and five TFV-encoded miRNAs in Groups H and Z, respectively. We compared the expression of TFV-encoded miRNAs from two groups and defined TFV-miR-11 as the essential viral miRNA and TFV-miR-13 and TFV-miR-14 as the specific miRNAs that contribute to HepG2 cell infection. CONCLUSIONS: We identified novel viral miRNAs and compared their expression in two host cells. The results of this study provide novel insights into the role of viral miRNAs in cross-species infection in vitro.

Expression of basic fibroblast growth factor, CD31, and α-smooth muscle actin and esophageal cancer recurrence after definitive chemoradiation.

There is cumulative evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. The aims of this study were to analyze the expression of basic fibroblast growth factor (FGF-2), CD31, and α-smooth muscle actin (SMA) in esophageal cancer patients and to establish their significance as indicators of disease recurrence after definitive chemoradiation (CRT). Protein expressions of FGF-2, CD31, and SMA were evaluated by immunohistochemistry and Western blot analysis in 70 patients, 20 with esophageal squamous cell carcinoma (ESCC) and 50 with locally recurrent ESCC after definitive CRT. Twenty matched normal esophageal squamous epithelium were also studied as controls. Esophageal cancer tissues showed positive expression of FGF-2, CD31, and SMA; in contrast, FGF-2 expression was not detected and only little staining for CD31 and SMA was noted in normal epithelium. Protein levels of FGF-2, CD31, and SMA were significantly elevated in recurrent ESCC. Among the patients with locally recurrent disease, expression of FGF-2 and SMA was notably high in whom the tumor recurred locally within 24 months after definitive CRT. The 2- and 5-year local recurrence-free survival rate was 15.4 % and 0 in patients with high FGF-2 expression, compared with 45.8 and 33.3 % in those who expressed low FGF-2, respectively (P = 0.005). Of patients who expressed high SMA, the 2- and 5-year local recurrence-free survival rate was 21.7 and 8.7 %, respectively, compared to those with low SMA expression which was 37.0 and 22.2 %, respectively (P = 0.016). Overexpression of FGF-2 and SMA is associated with local recurrence and reduced recurrence-free survival after definitive CRT for ESCC. The data also suggest that targeting stromal cells may be an attractive approach for esophageal cancer therapy strategies.

Expression profile of apoptosis-related genes potentially explains early recurrence after definitive chemoradiation in esophageal squamous cell carcinoma.

Definitive chemoradiation is a curative treatment option for patients with locoregional esophageal squamous cell carcinoma (ESCC) who are not suitable for surgical resection, but many tend to develop local recurrence. The purpose of the study was to investigate factors affecting local recurrence of the tumor. Seventy-two patients with stage II-III thoracic ESCC who received definitive concurrent chemoradiation (CRT) and completely responded to the treatment were enrolled into this study. The case patients were 49 patients who recurred locally within 24 months after definitive CRT and 23 patients who did not have a local recurrence within 24 months were considered as controls. We investigated whether dysregulation of apoptosis-related genes was associated with early tumor recurrence. Quantitative real-time polymerase chain reaction showed upregulation of BCLAF1 and downregulation of BAG4, CARD6, IGF1R, and TNF in the tissues of case patients, as compared with controls. Among the patients with recurrent ESCC, those with tumors which exhibited more than twofold upregulated BCLAF1 and more than twofold downregulated BAG4 and TNF had a decreased time interval to local recurrence. Three gene pairs of the downregulated genes showed a significant correlation with local recurrence: BAG4 and CARD6, BAG4 and TNF, CARD6, and TNF. The patients with T3-4 disease and those with tumor >3 cm in length had a trend toward early local recurrence, though the associations were not reached statistical significance. Upregulation of BCLAF1 and downregulation of BAG4 and TNF was independently associated with early local recurrence in multivariate analysis (P < 0.05). This study supports the involvement of apoptosis-related genes in early tumor recurrence after definitive chemoradiation in patients with stage II-III thoracic ESCC.

[The bio-effects of high single-dose radiation on xenografts of Lewis lung carcinoma].

OBJECTIVE: To investigate the bio-effects of high single-dose radiation on xenografts of Lewis lung carcinoma. METHODS: Female 8-week-old C57 mice bearing 4-6 mm diameter Lewis lung carcinoma tumors in the hind legs were divided into 3 groups, control group (0 Gy), high single-dose group (12 Gy/one fraction/day) and routine radiation group (22 Gy/11 fraction/15 d). The mean biological effective dose (BED) of both radiation groups was 26.4 Gy. Changes in hypoxia, DNA damage and cell cycle of the tumor cells at 1, 3, 8, 15 and 21 d after first irradiation was assessed by immunofluorescence and flow-cytometry and the tumor growth curve was also made. RESULTS: Compared to the fractionated treatment, the tumor growth was delayed after single dose irradiation. The percent of hypoxic cells after single dose radiation was lower than fractioned irradiation at 3, 8, 15 d after first radiation. The foci of gamma-H2AX showed that the single dose caused heavier DNA damages than fractioned irradiation at 1, 3 d after first radiation. The decline of G0/G1 percentage and increase of G2/M percentage of cells was found in both radiation schedules, but the G2/M percentage after single dose radiation was higher. CONCLUSION: In the C57 mice bearing Lewis lung carcinoma, the high single-dose regimen inhibits the tumor growth more than fractioned irradiation. We hypothesized that conversion of high single-dose to BED using the LQ formalism under estimated the in vivo effect of hypofractionated radiation.

Comparison of long-term survival of neoadjuvant therapy plus surgery versus upfront surgery and the role of adjuvant therapy for T1b-2N0-1 esophageal cancer: a population study of the SEER database and Chinese cohort.

BACKGROUND: For stage T1b-2N0-1 esophageal cancer, the impact of neoadjuvant therapy plus surgery (NS), surgery alone (SA), and surgery plus adjuvant therapy (ST) on cancer-specific survival (CSS) and overall survival (OS) is uncertain. METHODS: Stage T1b-2N0-1 esophageal cancer patients from the SEER database and two Chinese cancer centers were included in this study. The Kaplan-Meier method was used to plot survival curves, which were compared using the log-rank test. Propensity score matching was used to equalize differences between the groups. Cox proportional hazards regression models were used to analyze prognostic factors. A nomogram for OS was developed after screening the variables using the Cox proportional hazards regression model and the least absolute shrinkage and selection operator. The performance of the nomogram was assessed by the Harrell concordance index (C-index), the area under the curve (AUC) of the receiver operating characteristic curve, calibration plots, and decision curve analysis. RESULTS: After propensity score matching analysis, the 3-year CSS and OS rates in the NS group compared to the SA group were 80.3% versus 62.1% (P=0.016) and 75.8% versus 55.5% (P=0.006), the 3-year CSS and OS rates in the NS group compared to the ST group were 71.3% versus 68.3% (P=0.560) and 69.8% versus 62.9% (P=0.330), the 3-year CSS and OS rates in the SA group compared to the ST group were 54.6% versus 66.7% (P=0.220) and 50.2% versus 57.9% (P=0.290), respectively. The predictive nomogram for OS in T1b-2N0-1 patients ultimately incorporated five clinicopathological variables: T stage, N stage, age, examined lymph nodes , and therapy modality. The nomogram C-index for predicting OS was 0.648, 0.663, and 0.666 in the training group, external validation group-1, and external validation group-2, respectively. The 1-, 3-, and 5-year predicted AUC values of the OS prediction model were 0.659, 0.639, and 0.612 for the training group, and 0.786, 0.758, and 0.692 for validation group-1, and 0.805, 0.760, and 0.693 for validation group-2, respectively. CONCLUSION: For patients with stage T1b-2N0-1 esophageal cancer, neoadjuvant therapy significantly improves prognosis compared to surgery alone, those presenting with positive lymph nodes after upfront surgery can achieve survival benefits from adjuvant therapy.

MiR-3682-3p promotes esophageal cancer progression by targeting FHL1 and activating the Wnt/ß-catenin signaling pathway.

BACKGROUND: Esophageal cancer (EC) is highly ranked among all cancers in terms of its incidence and mortality rates. MicroRNAs (miRNAs) are considered to play key regulatory parts in EC. Multiple research studies have indicated the involvement of miR-3682-3p and four and a half LIM domain protein 1 (FHL1) in the achievement of tumors. The aim of this research was to clarify the significance of these genes and their possible molecular mechanism in EC. METHODS: Data from a database and the tissue microarray were made to analyze the expression and clinical significance of miR-3682-3p or FHL1 in EC. Reverse transcription quantitative PCR and Western blotting were used to detect the expression levels of miR-3682-3p and FHL1 in EC cells. CCK8, EdU, wound healing, Transwell, flow cytometry, and Western blotting assays were performed to ascertain the biological roles of miR-3682-3p and FHL1 in EC cells. To confirm the impact of miR-3682-3p in vivo, a subcutaneous tumor model was created in nude mice. The direct interaction between miR-3682-3p and FHL1 was demonstrated through a luciferase assay, and the western blotting technique was employed to assess the levels of crucial proteins within the Wnt/ß-catenin pathway. RESULTS: The noticeable increase in the expression of miR-3682-3p and the decrease in the expression of FHL1 were observed, which correlated with a negative impact on the patients' overall survival. Upregulation of miR-3682-3p expression promoted the growth and metastasis of EC, while overexpression of FHL1 partially reversed these effects. Finally, miR-3682-3p motivates the Wnt/ß-catenin signal transduction by directly targeting FHL1. CONCLUSION: MiR-3682-3p along the FHL1 axis activated the Wnt/ß-catenin signaling pathway and thus promoted EC malignancy.

Dihydroartemisinin remodels tumor micro-environment and improves cancer immunotherapy through inhibiting cyclin-dependent kinases.

Cancer immunotherapies are ineffective in nonresponding patients due to absence of immune responses. Here, we identified that dihydroartemisinin (DHA) induced immunogenic cell death (ICD) in hepatocellular carcinoma (HCC), proved by release or surface expose of damage-associated molecular patterns and in vivo protective vaccine activity. Mechanistically, DHA can inhibit cyclin-dependent kinases (CDKs), leading to a buildup of intracellular reactive oxygen species (ROS), which induces immunogenic cell death. In both Hepa1-6 and H22 tumor bearing mice, DHA exerted anti-tumor activity through increasing tumor-infiltrating CD8+ T cells with expression of activation makers (CD25 and CD69), secretion of intracellular cytokines (IFN-γ and TNF-α) and activated dendritic cells expressing MHCⅡ, CD80 and CD86. In hepa1-6 tumor bearing mice, DHA decreased immunosuppressive myeloid-derived suppressor cells. Furthermore, DHA enhanced the anti-PD-1 antibody and chimeric antigen receptor (CAR) T cell-mediated tumor suppression through recruitment and activation of endogenous CD8+ T cells. Overall, we demonstrated that by inhibiting CDKs, DHA can remodel tumor micro-environment to amplify anti-tumor immune responses in HCC. These findings provide a promising therapy option for HCC patients.

High-fidelity CRISPR/Cas12a dual-crRNA screening reveals novel synergistic interactions in hepatocellular carcinoma.

 : CRISPR/Cas12a-based combinational screening has shown remarkable potential for identifying genetic interactions. Here, we describe an innovative method for combinational genetic screening with rapid construction of a dual-CRISPR RNA (crRNA) library using gene splicing through overlap extension PCR (SOE PCR) and the adoption of CeCas12a, which we previously identified with strict PAM recognition and low off-targeting to guarantee fidelity and efficiency. The custom-pooled SOE crRNA array (SOCA) library for double-knockout screening could be conveniently constructed in the laboratory for widespread use, and the CeCas12a-mediated high-fidelity screen displayed good performance even under a negative selection screen. By designing a SOCA dual-crRNA library that covered most of the kinase and metabolism-associated gene targets of FDA-approved drugs implicated in hepatocellular carcinoma (HCC) tumourigenesis, novel cross-talk between the two gene sets was negatively selected to inhibit HCC cell growth in vitro and in vivo and was validated using virtual double-knockdown screening based on TCGA databases. Thus, this rapid, efficient and high-fidelity double-knockout screening system is promising for systemically identifying potential genetic interactions between multiple gene sets or combinations of FDA- approved drugs for clinical translational medicine in the future.

A metabolomic and proteomic study to elucidate the molecular mechanisms of immunotherapy resistance in patients with oesophageal squamous cell carcinoma.

Systemic chemotherapy, the standard first-line treatment option for patients with advanced oesophageal squamous cell carcinoma (OSCC), results in a median survival of ~1 year. Immune checkpoint inhibitors are a breakthrough oncology treatment option; however, most patients with advanced OSCC develop primary and acquired resistance to programmed death receptor-1 (PD-1) monoclonal antibody, severely affecting their prognosis. Therefore, there is an urgent need to investigate the molecular mechanism underlying resistance to treatment. The present study aimed to explore the mechanism of resistance to PD-1 monoclonal antibody. Plasma samples were collected from patients with OSCC treated with immunotherapy, who achieved pathological response/partial response (CR/PR) or stable disease/progressive disease (SD/PD) after the fourth treatment cycle. TM-widely targeted metabolomics, widely targeted lipidomics, and DIA proteomics assays were performed. Differential metabolites were screened based on fold change (FC) ≥1.5 or ≤0.67 and a VIP ≥1; differential proteins were screened based on FC >1.5 or <0.67 and P<0.05. The identified metabolites were annotated and mapped using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases. The differential proteins were annotated to the Gene Ontology and KEGG pathway databases. A correlation network diagram was drawn using differential expressed proteins and metabolites with (Pearson correlation coefficient) r>0.80 and P<0.05. Finally, 197 and 113 differential metabolites and proteins were screened, respectively, in patients with CR/PR and SD/PD groups. The KEGG enrichment analysis revealed that all of these metabolites and proteins were enriched in cholesterol metabolism and in the NF-κB and phospholipase D signalling pathways. The present study is the first to demonstrate that PD-1 inhibitor resistance may be attributed to cholesterol metabolism or NF-κB and phospholipase D signalling pathway activation. This finding suggests that targeting these signalling pathways may be a promising novel therapeutic approach in OSCC which may improve prognosis in patients undergoing immunotherapy.

Circ_0011385 knockdown inhibits cell proliferation, migration and invasion, whereas promotes cell apoptosis by regulating miR-330-3p/MYO6 axis in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a malignant tumor. Recent studies have showed circular RNA (circRNA) participates in the development of CRC. The study was designed to reveal the role of circ_0011385 in CRC progression and underneath mechanism. METHODS: The expression circ_0011385, microRNA-330-3p (miR-330-3p) and myosin VI (MYO6) mRNA were determined by quantitative real-time polymerase chain reaction. Protein expression was detected by Western blot assay. Cell proliferation was investigated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT), cell colony formation and flow cytometry assays. Cell apoptosis was demonstrated by flow cytometry analysis. Cell migration and invasion were evaluated by wound-healing assay and transwell invasion assay, respectively. The binding sites between miR-330-3p and circ_0011385 or MYO6 were predicted by CircInteractome or starBase online databases, and identified by dual-luciferase reporter and RNA immunoprecipitation assays. RESULTS: Circ_0011385 and MYO6 expression were dramatically upregulated, while miR-330-3p expression was downregulated in CRC tissues or cells compared with control groups. Circ_0011385 expression was associated with tumor size, tumor-node-metastasis stage (TNM) stage and lymph node metastasis of CRC patients. Circ_0011385 silencing or MYO6 absence repressed cell proliferation, migration and invasion, whereas induced cell apoptosis in CRC. Additionally, miR-330-3p inhibitor or MYO6 overexpression attenuated the repressive impacts of circ_0011385 silencing on CRC process. Circ_0011385 was associated with miR-330-3p, and miR-330-3p targeted MYO6. Circ_0011385 knockdown inactivated MEK1/2/ERK1/2 signaling pathway by miR-330-3p/MYO6 axis. Furthermore, circ_0011385 knockdown suppressed tumor growth in vivo. CONCLUSION: Circ_0011385 regulated CRC process by miR-330-3p/MYO6 axis through MEK1/2/ERK1/2 signaling pathway, providing a novel therapeutic target for CRC.