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On page 1 showing 1 ~ 20 papers out of 35 papers

Altered effective connectivity of posterior thalamus in migraine with cutaneous allodynia: a resting-state fMRI study with Granger causality analysis.

  • Ting Wang‎ et al.
  • The journal of headache and pain‎
  • 2015‎

Most migraineurs develop cutaneous allodynia (CA) during migraine, and the underlying mechanism of CA in migraine is thought to be sensitization of the third-order trigeminovascular neurons in the posterior thalamic nuclei. This study aimed to investigate whether the ascending/descending pathway associated with the thalamus is disturbed in migraineurs with CA (MWCA) using effective connectivity analysis of resting-state functional magnetic resonance imaging.


MicroRNA-17 Modulates Regulatory T Cell Function by Targeting Co-regulators of the Foxp3 Transcription Factor.

  • Huang-Yu Yang‎ et al.
  • Immunity‎
  • 2016‎

Regulatory T (Treg) cells are important in maintaining self-tolerance and immune homeostasis. The Treg cell transcription factor Foxp3 works in concert with other co-regulatory molecules, including Eos, to determine the transcriptional signature and characteristic suppressive phenotype of Treg cells. Here, we report that the inflammatory cytokine interleukin-6 (IL-6) actively repressed Eos expression through microRNA-17 (miR-17). miR-17 expression increased in Treg cells in the presence of IL-6, and its expression negatively correlated with that of Eos. Treg cell suppressive activity was diminished upon overexpression of miR-17 in vitro and in vivo, which was mitigated upon co-expression of an Eos mutant lacking miR-17 target sites. Also, RNAi of miR-17 resulted in enhanced suppressive activity. Ectopic expression of miR-17 imparted effector-T-cell-like characteristics to Treg cells via the de-repression of genes encoding effector cytokines. Thus, miR-17 provides a potent layer of Treg cell control through targeting Eos and additional Foxp3 co-regulators.


A dual role of BRCA1 in two distinct homologous recombination mediated repair in response to replication arrest.

  • Zhihui Feng‎ et al.
  • Nucleic acids research‎
  • 2012‎

Homologous recombination (HR) is a major mechanism utilized to repair blockage of DNA replication forks. Here, we report that a sister chromatid exchange (SCE) generated by crossover-associated HR efficiently occurs in response to replication fork stalling before any measurable DNA double-strand breaks (DSBs). Interestingly, SCE produced by replication fork collapse following DNA DSBs creation is specifically suppressed by ATR, a central regulator of the replication checkpoint. BRCA1 depletion leads to decreased RPA2 phosphorylation (RPA2-P) following replication fork stalling but has no obvious effect on RPA2-P following replication fork collapse. Importantly, we found that BRCA1 promotes RAD51 recruitment and SCE induced by replication fork stalling independent of ATR. In contrast, BRCA1 depletion leads to a more profound defect in RAD51 recruitment and SCE induced by replication fork collapse when ATR is depleted. We concluded that BRCA1 plays a dual role in two distinct HR-mediated repair upon replication fork stalling and collapse. Our data established a molecular basis for the observation that defective BRCA1 leads to a high sensitivity to agents that cause replication blocks without being associated with DSBs, and also implicate a novel mechanism by which loss of cell cycle checkpoints promotes BRCA1-associated tumorigenesis via enhancing HR defect resulting from BRCA1 deficiency.


BRCA1 loss activates cathepsin L-mediated degradation of 53BP1 in breast cancer cells.

  • David A Grotsky‎ et al.
  • The Journal of cell biology‎
  • 2013‎

Loss of 53BP1 rescues BRCA1 deficiency and is associated with BRCA1-deficient and triple-negative breast cancers (TNBC) and with resistance to genotoxic drugs. The mechanisms responsible for decreased 53BP1 transcript and protein levels in tumors remain unknown. Here, we demonstrate that BRCA1 loss activates cathepsin L (CTSL)-mediated degradation of 53BP1. Activation of this pathway rescued homologous recombination repair and allowed BRCA1-deficient cells to bypass growth arrest. Importantly, depletion or inhibition of CTSL with vitamin D or specific inhibitors stabilized 53BP1 and increased genomic instability in response to radiation and poly(adenosine diphosphate-ribose) polymerase inhibitors, compromising proliferation. Analysis of human breast tumors identified nuclear CTSL as a positive biomarker for TNBC, which correlated inversely with 53BP1. Importantly, nuclear levels of CTSL, vitamin D receptor, and 53BP1 emerged as a novel triple biomarker signature for stratification of patients with BRCA1-mutated tumors and TNBC, with potential predictive value for drug response. We identify here a novel pathway with prospective relevance for diagnosis and customization of breast cancer therapy.


Small-Molecule-Mediated Stabilization of PP2A Modulates the Homologous Recombination Pathway and Potentiates DNA Damage-Induced Cell Death.

  • Rita A Avelar‎ et al.
  • Molecular cancer therapeutics‎
  • 2023‎

High-grade serous carcinoma (HGSC) is the most common and lethal ovarian cancer subtype. PARP inhibitors (PARPi) have become the mainstay of HGSC-targeted therapy, given that these tumors are driven by a high degree of genomic instability (GI) and homologous recombination (HR) defects. Nonetheless, approximately 30% of patients initially respond to treatment, ultimately relapsing with resistant disease. Thus, despite recent advances in drug development and an increased understanding of genetic alterations driving HGSC progression, mortality has not declined, highlighting the need for novel therapies. Using a small-molecule activator of protein phosphatase 2A (PP2A; SMAP-061), we investigated the mechanism by which PP2A stabilization induces apoptosis in patient-derived HGSC cells and xenograft (PDX) models alone or in combination with PARPi. We uncovered that PP2A genes essential for cellular transformation (B56α, B56γ, and PR72) and basal phosphatase activity (PP2A-A and -C) are heterozygously lost in the majority of HGSC. Moreover, loss of these PP2A genes correlates with worse overall patient survival. We show that SMAP-061-induced stabilization of PP2A inhibits the HR output by targeting RAD51, leading to chronic accumulation of DNA damage and ultimately apoptosis. Furthermore, combination of SMAP-061 and PARPi leads to enhanced apoptosis in both HR-proficient and HR-deficient HGSC cells and PDX models. Our studies identify PP2A as a novel regulator of HR and indicate PP2A modulators as a therapeutic therapy for HGSC. In summary, our findings further emphasize the potential of PP2A modulators to overcome PARPi insensitivity, given that targeting RAD51 presents benefits in overcoming PARPi resistance driven by BRCA1/2 mutation reversions.


Determination of DNA lesion bypass using a ChIP-based assay.

  • Dayong Wu‎ et al.
  • DNA repair‎
  • 2021‎

DNA lesion bypass facilitates DNA synthesis across bulky DNA lesions, playing a critical role in DNA damage tolerance and cell survival after DNA damage. Assessing lesion bypass efficiency in the cell is important to better understanding of the mechanism of carcinogenesis and chemoresistance. Here we developed a chromatin immunoprecipitation (ChIP)-based method to measure lesion bypass activity across cisplatin-induced intrastrand crosslinks in cancer cells. DNA lesion bypass enables the replication to continue in the presence of replication blocks. Thus, the successful lesion bypass should result in the coexistence of DNA lesions and the newly synthesized DNA fragment opposite to this lesion. Using ChIP, we precipitated the cisplatin-induced intrastrand crosslinks, and quantitated the precipitated newly synthesized DNA that was labeled with BrdU. We validated this method on ovarian cancer cells with inhibited TLS activity. We then applied this method to show that ovarian cancer stem cells exhibit high lesion bypass activity relative to bulk cancer cells from the same cell line. In conclusion, this novel ChIP-based lesion bypass assay can detect the extent to which cisplatin-induced DNA lesions are bypassed in live cells. Our study may be applied more broadly to the study of other DNA lesions, as specific antibodies to these specific lesions are available.


ALDH1A1 promotes PARP inhibitor resistance by enhancing retinoic acid receptor-mediated DNA polymerase θ expression.

  • Kousalya Lavudi‎ et al.
  • NPJ precision oncology‎
  • 2023‎

Poly (ADP-ribose) Polymerase (PARP) inhibitors (PARPi) have been approved for both frontline and recurrent setting in ovarian cancer with homologous recombination (HR) repair deficiency. However, more than 40% of BRCA1/2-mutated ovarian cancer lack the initial response to PARPi treatment, and the majority of those that initially respond eventually develop resistance. Our previous study has demonstrated that increased expression of aldehyde dehydrogenase 1A1 (ALDH1A1) contributes to PARPi resistance in BRCA2-mutated ovarian cancer cells by enhancing microhomology-mediated end joining (MMEJ) but the mechanism remains unknown. Here, we find that ALDH1A1 enhances the expression of DNA polymerase θ (Polθ, encoded by the POLQ gene) in ovarian cancer cells. Furthermore, we demonstrate that the retinoic acid (RA) pathway is involved in the transcription activation of the POLQ gene. The RA receptor (RAR) can bind to the retinoic acid response element (RARE) located in the promoter of the POLQ gene, promoting transcription activation-related histone modification in the presence of RA. Given that ALDH1A1 catalyzes the biosynthesis of RA, we conclude that ALDH1A1 promotes POLQ expression via the activation of the RA signaling pathway. Finally, using a clinically-relevant patient-derived organoid (PDO) model, we find that ALDH1A1 inhibition by the pharmacological inhibitor NCT-505 in combination with the PARP inhibitor olaparib synergistically reduce the cell viability of PDOs carrying BRCA1/2 mutation and positive ALDH1A1 expression. In summary, our study elucidates a new mechanism contributing to PARPi resistance in HR-deficient ovarian cancer and shows the therapeutic potential of combining PARPi and ALDH1A1 inhibition in treating these patients.


Closely Spaced MEG Source Localization and Functional Connectivity Analysis Using a New Prewhitening Invariance of Noise Space Algorithm.

  • Junpeng Zhang‎ et al.
  • Neural plasticity‎
  • 2016‎

This paper proposed a prewhitening invariance of noise space (PW-INN) as a new magnetoencephalography (MEG) source analysis method, which is particularly suitable for localizing closely spaced and highly correlated cortical sources under real MEG noise. Conventional source localization methods, such as sLORETA and beamformer, cannot distinguish closely spaced cortical sources, especially under strong intersource correlation. Our previous work proposed an invariance of noise space (INN) method to resolve closely spaced sources, but its performance is seriously degraded under correlated noise between MEG sensors. The proposed PW-INN method largely mitigates the adverse influence of correlated MEG noise by projecting MEG data to a new space defined by the orthogonal complement of dominant eigenvectors of correlated MEG noise. Simulation results showed that PW-INN is superior to INN, sLORETA, and beamformer in terms of localization accuracy for closely spaced and highly correlated sources. Lastly, source connectivity between closely spaced sources can be satisfactorily constructed from source time courses estimated by PW-INN but not from results of other conventional methods. Therefore, the proposed PW-INN method is a promising MEG source analysis to provide a high spatial-temporal characterization of cortical activity and connectivity, which is crucial for basic and clinical research of neural plasticity.


BACH1 is critical for homologous recombination and appears to be the Fanconi anemia gene product FANCJ.

  • Rachel Litman‎ et al.
  • Cancer cell‎
  • 2005‎

We showed in this study that cells deficient of the BRCA1-associated BACH1 helicase, also known as BRIP1, failed to elicit homologous recombination (HR) after DNA double-stranded breaks (DSBs). BACH1-deficient cells were also sensitive to mitomycin C (MMC) and underwent MMC-induced chromosome instability. Moreover, we identified a homozygous nonsense mutation in BACH1 in a FA-J patient-derived cell line and could not detect BACH1 protein in this cell line. Expression of wild-type BACH1 in this cell line reduced the accumulation of cells at G2/M phases following exposure to DNA crosslinkers, a characteristic of Fanconi anemia (FA) cells. These results support the conclusion that BACH1 is FANCJ.


Multimodal MRI-based classification of migraine: using deep learning convolutional neural network.

  • Hao Yang‎ et al.
  • Biomedical engineering online‎
  • 2018‎

Recently, deep learning technologies have rapidly expanded into medical image analysis, including both disease detection and classification. As far as we know, migraine is a disabling and common neurological disorder, typically characterized by unilateral, throbbing and pulsating headaches. Unfortunately, a large number of migraineurs do not receive the accurate diagnosis when using traditional diagnostic criteria based on the guidelines of the International Headache Society. As such, there is substantial interest in developing automated methods to assist in the diagnosis of migraine.


Research of cerebral activation in Uygur-speaking and Chinese-speaking participants during verb generation task with functional magnetic resonance imaging.

  • Yanling Xi‎ et al.
  • Medicine‎
  • 2017‎

The aims are to investigate and compare the activated cerebral regions of Uygur-speaking and Chinese-speaking participants during verb generation task.A total of 31 cases of Uygur and 28 cases of Han healthy volunteers were enrolled. They were requested to take verb generation tasks. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) was performed. The fMRI images were collected and activated brain regions were analyzed.In Chinese-speaking participants, the main activated cerebral regions were as follows: the left caudate nucleus, the left occipital gyrus, the left fusiform gyrus, bilateral supplementary motor area (BA8/ 6), the left BA32, left precuneus, the left superior parietal lobule, the left inferior parietal lobule (BA7), the left angular gyrus, the right side of the central gyrus (BA9), the left inferior frontal gyrus triangular section, the right pars opercularis gyri frontalis inferiorista, and bilateral cerebellum. In Uygur-speaking subjects, the main activated cerebral regions included left precentral gyrus (BA9 region), inferior frontal gyrus of left opercular part, inferior frontal gyrus of left triangle part, and left cerebellum. Left caudate nucleus, left orbital frontal gyrus, right caudate nucleus, and bilateral anterior cingulate gyrus (BA32 region) of Chinese group were significantly activated compared with Uygur group. By contrast, Uygur group showed no region that was more activated than Chinese group.The present study demonstrates that activated brain regions in verb generation tasks are different between Uygur and Chinese languages. Processing of Uygur characters is mainly in the left hemisphere of the brain, while the processing of Chinese characters needs more participation by the right hemisphere of the brain.


ERK inactivation enhances stemness of NSCLC cells via promoting Slug-mediated epithelial-to-mesenchymal transition.

  • Shurui Cai‎ et al.
  • Theranostics‎
  • 2022‎

Rationale: The mitogen-activated protein kinase pathway (MAPK) is one of the major cancer-driving pathways found in non-small cell lung cancer (NSCLC) patients. ERK inhibitors (ERKi) have been shown to be effective in NSCLC patients with MAPK pathway mutations. However, like other MAPK inhibitors, ERKi rarely confers complete and durable responses. The mechanism of tumor relapse after ERKi treatment is yet defined. Methods: To best study the mechanism of tumor relapse after ERK inhibitor treatment in NSCLC patients, we treated various NSCLC cell lines and patient-derived xenograft (PDX) with ERK inhibitors and evaluated the enrichment of cancer stem cell (CSC) population. We then performed a Next-generation sequencing (NGS) to identify potential pathways that are responsible for the CSC enrichment. Further, the involvement of specific pathways was examined using molecular and cellular methods. Finally, we investigated the therapeutic benefits of ERKi treatment combined with JAK/STAT pathway inhibitor using cellular and xenograft NSCLC models. Results: We found that ERKi treatment expands the CSC population in NSCLC cells through enhanced epithelial-to-mesenchymal transition (EMT)-mediated cancer cell dedifferentiation. Mechanistically, ERK inactivation induces EMT via pSTAT3-mediated upregulation of Slug, in which, upregulation of miR-204 and downregulation of SPDEF, a transcription repressor of Slug, are involved. Finally, the JAK/STAT pathway inhibitor Ruxolitinib blocks the ERK inactivation-induced EMT and CSC expansion, as well as the tumor progression in xenograft models after ERKi treatment. Conclusions: This study revealed a potential tumor relapse mechanism of NSCLC after ERK inhibition through the unintended activation of the EMT program, ascertained the pSTAT-miR-204-SPDEF-Slug axis, and provided a promising combination inhibitor approach to prevent tumor relapse in patients.


The thioredoxin system determines CHK1 inhibitor sensitivity via redox-mediated regulation of ribonucleotide reductase activity.

  • Chandra Bhushan Prasad‎ et al.
  • Research square‎
  • 2023‎

Checkpoint kinase 1 (CHK1) is critical for cell survival under replication stress (RS). CHK1 inhibitors (CHK1i's) in combination with chemotherapy have shown promising results in preclinical studies but minimal efficacy with substantial toxicity in clinical trials. To explore novel combinational strategies that can overcome these limitations, we performed an unbiased high-throughput screen in a non-small cell lung cancer (NSCLC) cell line and identified thioredoxin1 (Trx1), a major component of the mammalian antioxidant-system, as a novel determinant of CHK1i sensitivity. We established a role for redox recycling of RRM1, the larger subunit of ribonucleotide reductase (RNR), and a depletion of the deoxynucleotide pool in this Trx1-mediated CHK1i sensitivity. Further, the TrxR1 inhibitor auronafin, an anti-rheumatoid arthritis drug, shows a synergistic interaction with CHK1i via interruption of the deoxynucleotide pool. Together, these findings identify a new pharmacological combination to treat NSCLC that relies on a redox regulatory link between the Trx system and mammalian RNR activity.


53BP1 promotes microhomology-mediated end-joining in G1-phase cells.

  • Xiahui Xiong‎ et al.
  • Nucleic acids research‎
  • 2015‎

Alternative non-homologous end joining (alt-NHEJ) was originally identified as a backup repair mechanism in the absence of classical NHEJ (c-NHEJ) factors but recent studies have demonstrated that alt-NHEJ is active even when c-NHEJ as well as homologous recombination is available. The functions of 53BP1 in NHEJ processes are not well understood. Here, we report that 53BP1 promotes DNA double-strand break (DSB) repair and genomic stability not only in c-NHEJ-proficient but also -deficient human G1-phase cells. Using an array of repair substrates we show that these effects of 53BP1 are correlated with a promotion of microhomology-mediated end-joining (MMEJ), a subtype of alt-NHEJ, in G1-phase. Consistent with a specific role in MMEJ we confirm that 53BP1 status does not affect c-NHEJ. 53BP1 supports sequence deletion during MMEJ consistent with a putative role in facilitating end-resection. Interestingly, promotion of MMEJ by 53BP1 in G1-phase cells is only observed in the presence of functional BRCA1. Depletion of both 53BP1 and BRCA1 increases repair needing microhomology usage and augments loss of DNA sequence, suggesting that MMEJ is a highly regulated DSB repair process. Together, these findings significantly expand our understanding of the cell-cycle-dependent roles of 53BP1 in DSB repair.


Multimodal MRI-Based Classification of Trauma Survivors with and without Post-Traumatic Stress Disorder.

  • Qiongmin Zhang‎ et al.
  • Frontiers in neuroscience‎
  • 2016‎

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric disorder. It can be difficult to discern the symptoms of PTSD and obtain an accurate diagnosis. Different magnetic resonance imaging (MRI) modalities focus on different aspects, which may provide complementary information for PTSD discrimination. However, none of the published studies assessed the diagnostic potential of multimodal MRI in identifying individuals with and without PTSD. In the current study, we investigated whether the complementary information conveyed by multimodal MRI scans could be combined to improve PTSD classification performance. Structural and resting-state functional MRI (rs-fMRI) scans were conducted on 17 PTSD patients, 20 trauma-exposed controls without PTSD (TEC) and 20 non-traumatized healthy controls (HC). Gray matter volume (GMV), amplitude of low-frequency fluctuations (ALFF), and regional homogeneity were extracted as classification features, and in order to integrate the information of structural and functional MRI data, the extracted features were combined by a multi-kernel combination strategy. Then a support vector machine (SVM) classifier was trained to distinguish the subjects at individual level. The performance of the classifier was evaluated using the leave-one-out cross-validation (LOOCV) method. In the pairwise comparison of PTSD, TEC, and HC groups, classification accuracies obtained by the proposed approach were 2.70, 2.50, and 2.71% higher than the best single feature way, with the accuracies of 89.19, 90.00, and 67.57% for PTSD vs. HC, TEC vs. HC, and PTSD vs. TEC respectively. The proposed approach could improve PTSD identification at individual level. Additionally, it provides preliminary support to develop the multimodal MRI method as a clinical diagnostic aid.


Discriminative Analysis of Migraine without Aura: Using Functional and Structural MRI with a Multi-Feature Classification Approach.

  • Qiongmin Zhang‎ et al.
  • PloS one‎
  • 2016‎

Magnetic resonance imaging (MRI) is by nature a multi-modality technique that provides complementary information about different aspects of diseases. So far no attempts have been reported to assess the potential of multi-modal MRI in discriminating individuals with and without migraine, so in this study, we proposed a classification approach to examine whether or not the integration of multiple MRI features could improve the classification performance between migraine patients without aura (MWoA) and healthy controls. Twenty-one MWoA patients and 28 healthy controls participated in this study. Resting-state functional MRI data was acquired to derive three functional measures: the amplitude of low-frequency fluctuations, regional homogeneity and regional functional correlation strength; and structural MRI data was obtained to measure the regional gray matter volume. For each measure, the values of 116 pre-defined regions of interest were extracted as classification features. Features were first selected and combined by a multi-kernel strategy; then a support vector machine classifier was trained to distinguish the subjects at individual level. The performance of the classifier was evaluated using a leave-one-out cross-validation method, and the final classification accuracy obtained was 83.67% (with a sensitivity of 92.86% and a specificity of 71.43%). The anterior cingulate cortex, prefrontal cortex, orbitofrontal cortex and the insula contributed the most discriminative features. In general, our proposed framework shows a promising classification capability for MWoA by integrating information from multiple MRI features.


AIB1 is a novel target of the high-risk HPV E6 protein and a biomarker of cervical cancer progression.

  • Jonathan Miller‎ et al.
  • Journal of medical virology‎
  • 2022‎

The high-risk human papillomaviruses (HPV-16, -18) are critical etiologic agents in human malignancy, most importantly in cervical cancer. These oncogenic viruses encode the E6 and E7 proteins that are uniformly retained and expressed in cervical cancers and required for maintenance of the tumorigenic phenotype. The E6 and E7 proteins were first identified as targeting the p53 and pRB tumor suppressor pathways, respectively, in host cells, thereby leading to disruption of cell cycle controls. In addition to p53 degradation, a number of other functions and critical targets for E6 have been described, including telomerase, Myc, PDZ-containing proteins, Akt, Wnt, mTORC1, as well as others. In this study, we identified Amplified in Breast Cancer 1 (AIB1) as a new E6 target. We first found that E6 and hTERT altered similar profiling of gene expression in human foreskin keratinocytes (HFK), independent of telomerase activity. Importantly, AIB1 was a common transcriptional target of both E6 and hTERT. We then verified that high-risk E6 but not low-risk E6 expression led to increases in AIB1 transcript levels by real-time RT-PCR, suggesting that AIB1 upregulation may play an important role in cancer development. Western blots demonstrated that AIB1 expression increased in HPV-16 E6 and E7 expressing (E6E7) immortalized foreskin and cervical keratinocytes, and in three of four common cervical cancer cell lines as well. Then, we evaluated the expression of AIB1 in human cervical lesions and invasive carcinoma using immunohistochemical staining. Strikingly, AIB1 showed positivity in the nucleus of cells in the immediate suprabasal epithelium, while nuclei of the basal epithelium were negative, as evident in the Cervical Intraepithelial Neoplasia 1 (CIN1) samples. As the pathological grading of cervical lesions increased from CIN1, CIN2, CIN3 carcinoma in situ and invasive carcinoma, AIB1 staining increased progressively, suggesting that AIB1 may serve as a novel histological biomarker for cervical cancer development. For cases of invasive cervical carcinoma, AIB1 staining was specific to cancerous lesions. Increased expression of AIB1 was also observed in transgenic mouse cervical neoplasia and cancer models induced by E6E7 and estrogen. Knockdown of AIB1 expression in E6E7 immortalized human cervical cells significantly abolished cell proliferation. Taken together, these data support AIB1 as a novel target of HPV E6 and a biomarker of cervical cancer progression.


Human constitutive androstane receptor represses liver cancer development and hepatoma cell proliferation by inhibiting erythropoietin signaling.

  • Zhihui Li‎ et al.
  • The Journal of biological chemistry‎
  • 2022‎

The constitutive androstane receptor (CAR) is a nuclear receptor that plays a crucial role in regulating xenobiotic metabolism and detoxification, energy homeostasis, and cell proliferation by modulating the transcription of numerous target genes. CAR activation has been established as the mode of action by which phenobarbital-like nongenotoxic carcinogens promote liver tumor formation in rodents. This paradigm, however, appears to be unrelated to the function of human CAR (hCAR) in hepatocellular carcinoma (HCC), which remains poorly understood. Here, we show that hCAR expression is significantly lower in HCC than that in adjacent nontumor tissues and, importantly, reduced hCAR expression is associated with a worse HCC prognosis. We also show overexpression of hCAR in human hepatoma cells (HepG2 and Hep3B) profoundly suppressed cell proliferation, cell cycle progression, soft-agar colony formation, and the growth of xenografts in nude mice. RNA-Seq analysis revealed that the expression of erythropoietin (EPO), a pleiotropic growth factor, was markedly repressed by hCAR in hepatoma cells. Addition of recombinant EPO in HepG2 cells partially rescued hCAR-suppressed cell viability. Mechanistically, we showed that overexpressing hCAR repressed mitogenic EPO-EPO receptor signaling through dephosphorylation of signal transducer and activator of transcription 3, AKT, and extracellular signal-regulated kinase 1/2. Furthermore, we found that hCAR downregulates EPO expression by repressing the expression and activity of hepatocyte nuclear factor 4 alpha, a key transcription factor regulating EPO expression. Collectively, our results suggest that hCAR plays a tumor suppressive role in HCC development, which differs from that of rodent CAR and offers insight into the hCAR-hepatocyte nuclear factor 4 alpha-EPO axis in human liver tumorigenesis.


Micropeptide PACMP inhibition elicits synthetic lethal effects by decreasing CtIP and poly(ADP-ribosyl)ation.

  • Chuanchao Zhang‎ et al.
  • Molecular cell‎
  • 2022‎

Synthetic lethality through combinatorial targeting DNA damage response (DDR) pathways provides exciting anticancer therapeutic benefit. Currently, the long noncoding RNAs (lncRNAs) have been implicated in tumor drug resistance; however, their potential significance in DDR is still largely unknown. Here, we report that a human lncRNA, CTD-2256P15.2, encodes a micropeptide, named PAR-amplifying and CtIP-maintaining micropeptide (PACMP), with a dual function to maintain CtIP abundance and promote poly(ADP-ribosyl)ation. PACMP not only prevents CtIP from ubiquitination through inhibiting the CtIP-KLHL15 association but also directly binds DNA damage-induced poly(ADP-ribose) chains to enhance PARP1-dependent poly(ADP-ribosyl)ation. Targeting PACMP alone inhibits tumor growth by causing a synthetic lethal interaction between CtIP and PARP inhibitions and confers sensitivity to PARP/ATR/CDK4/6 inhibitors, ionizing radiation, epirubicin, and camptothecin. Our findings reveal that a lncRNA-derived micropeptide regulates cancer progression and drug resistance by modulating DDR, whose inhibition could be employed to augment the existing anticancer therapeutic strategies.


Structural and Functional Abnormalities in Knee Osteoarthritis Pain Revealed With Multimodal Magnetic Resonance Imaging.

  • Hua Guo‎ et al.
  • Frontiers in human neuroscience‎
  • 2021‎

The knee osteoarthritis (KOA) pain is the most common form of arthritis pain affecting millions of people worldwide. Long-term KOA pain causes motor impairment and affects affective and cognitive functions. However, little is known about the structural and functional abnormalities induced by long-term KOA pain. In this work, high-resolution structural magnetic resonance imaging (sMRI) and resting-state functional MRI (rs-fMRI) data were acquired in patients with KOA and age-, sex-matched healthy controls (HC). Gray matter volume (GMV) and fractional amplitude of low-frequency fluctuation (fALFF) were used to study the structural and functional abnormalities in patients with KOA. Compared with HC, patients with KOA showed reduced GMV in bilateral insula and bilateral hippocampus, and reduced fALFF in left cerebellum, precentral gyrus, and the right superior occipital gyrus. Patients with KOA also showed increased fALFF in left insula and bilateral hippocampus. In addition, the abnormal GMV in left insula and fALFF in left fusiform were closely correlated with the pain severity or disease duration. These results indicated that long KOA pain leads to brain structural and functional impairments in motor, visual, cognitive, and affective functions that related to brain areas. Our findings may facilitate to understand the neural basis of KOA pain and the future therapy to relieve disease symptoms.


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