Human lung cancer harbors spatially organized stem-immunity hubs associated with response to immunotherapy.

The organization of immune cells in human tumors is not well understood. Immunogenic tumors harbor spatially localized multicellular 'immunity hubs' defined by expression of the T cell-attracting chemokines CXCL10/CXCL11 and abundant T cells. Here, we examined immunity hubs in human pre-immunotherapy lung cancer specimens and found an association with beneficial response to PD-1 blockade. Critically, we discovered the stem-immunity hub, a subtype of immunity hub strongly associated with favorable PD-1-blockade outcome. This hub is distinct from mature tertiary lymphoid structures and is enriched for stem-like TCF7+PD-1+CD8+ T cells, activated CCR7+LAMP3+ dendritic cells and CCL19+ fibroblasts as well as chemokines that organize these cells. Within the stem-immunity hub, we find preferential interactions between CXCL10+ macrophages and TCF7-CD8+ T cells as well as between mature regulatory dendritic cells and TCF7+CD4+ and regulatory T cells. These results provide a picture of the spatial organization of the human intratumoral immune response and its relevance to patient immunotherapy outcomes.

Non-severe thermal burn injuries induce long-lasting downregulation of gene expression in cortical excitatory neurons and microglia.

Burn injuries are devastating traumas, often leading to life-long consequences that extend beyond the observable burn scar. In the context of the nervous system, burn injury patients commonly develop chronic neurological disorders and have been suggested to have impaired motor cortex function, but the long-lasting impact on neurons and glia in the brain is unknown. Using a mouse model of non-severe burn injury, excitatory and inhibitory neurons in the primary motor cortex were labelled with fluorescent proteins using adeno-associated viruses (AAVs). A total of 5 weeks following the burn injury, virus labelled excitatory and inhibitory neurons were isolated using fluorescence-activated cell sorting (FACS). In addition, microglia and astrocytes from the remaining cortical tissue caudal to the motor cortex were immunolabelled and isolated with FACS. Whole transcriptome RNA-sequencing was used to identify any long-lasting changes to gene expression in the different cell types. RNA-seq analysis showed changes to the expression of a small number of genes with known functions in excitatory neurons and microglia, but not in inhibitory neurons or astrocytes. Specifically, genes related to GABA-A receptors in excitatory neurons and several cellular functions in microglia were found to be downregulated in burn injured mice. These findings suggest that non-severe burn injuries lead to long lasting transcriptomic changes in the brain, but only in specific cell types. Our findings provide a broad overview of the long-lasting impact of burn injuries on the central nervous system which may help identify potential therapeutic targets to prevent neurological dysfunction in burn patients.

Cauda equina syndrome in a patient with human immunodeficiency virus and secondary central nervous system lymphoma: a case report.

BACKGROUND: Secondary central nervous system lymphoma (SCNSL) is a known complication of immunocompromised patients with most cases involving the brain parenchyma. Reports of cauda equina syndrome (CES) caused by SCNSL are exceedingly scarce as involvement of this anatomical region is extremely uncommon. CASE PRESENTATION: We report a case of a 46-years-old, African, female patient with human immunodeficiency virus (HIV) who developed CES in the context of SCNSL. There were no blasts present in the peripheral blood smear. We provide a review of the literature, discussion of the clinical evolution of this patient and the radiological/histopathological findings. The patient ultimately responded well to induction chemotherapy and high dose methotrexate. CONCLUSION: This case report demonstrates that CES, while a rare occurrence in this clinical context, should be considered in at-risk patients especially those presenting with abnormal neurological findings. Prompt recognition may prevent permanent neurological injury and obviate the need for more invasive therapeutic interventions.

Clathrin light chain A facilitates small extracellular vesicle uptake to promote hepatocellular carcinoma progression.

BACKGROUND: Endocytosis is a fundamental process for internalizing small extracellular vesicles (sEVs). The present study aimed to elucidate the role of clathrin light chain A (CLTA) in sEV uptake in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: CLTA expression was analyzed by bioinformatics, quantitative PCR and immunohistochemistry. The clinical relevance of CLTA was analyzed by Fisher's exact test, Kaplan-Meier analysis, and multivariate cox regression model. The functions of CLTA in sEV uptake and cancerous properties were examined by PKH67-sEV uptake, MTT, colony formation, and transwell assays. Mass spectrometry was used to identify the downstream effectors of CLTA. CLTA inhibitor, Pitstop 2, was tested in a mouse model of patient-derived xenografts (PDXs). RESULTS: CLTA expression was higher in tumor tissues than in non-tumorous liver tissues and progressively increased from the early to late tumor stage. CLTA overexpression was associated with larger tumor size and poor prognosis in HCC. Cellular CLTA contributed to the sEV uptake, resulting in enhanced cancerous properties. Mechanistically, CLTA increases capping actin protein gelsolin-like (CAPG) expression to facilitate sEV uptake, thereby promoting the proliferation, motility, and invasiveness of HCC cells. What's more, the CLTA inhibitor Pitstop 2 alone or in combination with sorafenib attenuated tumor growth in mice implanted with PDXs. CONCLUSIONS: The study reveals the role of CLTA in sEV uptake to promote HCC progression. Inhibition of CLTA and its mediated pathway illuminate a new therapeutic strategy for HCC patients.

Spatial analysis of human lung cancer reveals organized immune hubs enriched for stem-like CD8 T cells and associated with immunotherapy response.

The organization of immune cells in human tumors is not well understood. Immunogenic tumors harbor spatially-localized multicellular 'immunity hubs' defined by expression of the T cell-attracting chemokines CXCL10/CXCL11 and abundant T cells. Here, we examined immunity hubs in human pre-immunotherapy lung cancer specimens, and found that they were associated with beneficial responses to PD-1-blockade. Immunity hubs were enriched for many interferon-stimulated genes, T cells in multiple differentiation states, and CXCL9/10/11 + macrophages that preferentially interact with CD8 T cells. Critically, we discovered the stem-immunity hub, a subtype of immunity hub strongly associated with favorable PD-1-blockade outcomes, distinct from mature tertiary lymphoid structures, and enriched for stem-like TCF7+PD-1+ CD8 T cells and activated CCR7 + LAMP3 + dendritic cells, as well as chemokines that organize these cells. These results elucidate the spatial organization of the human intratumoral immune response and its relevance to patient immunotherapy outcomes.

Magnetic temporal interference for noninvasive and focal brain stimulation.

Objective. Noninvasive focal stimulation of deep brain regions has been a major goal for neuroscience and neuromodulation in the past three decades. Transcranial magnetic stimulation (TMS), for instance, cannot target deep regions in the brain without activating the overlying tissues and has poor spatial resolution. In this manuscript, we propose a new concept that relies on the temporal interference (TI) of two high-frequency magnetic fields generated by two electromagnetic solenoids.Approach. To illustrate the concept, custom solenoids were fabricated and optimized to generate temporal interfering electric fields for rodent brain stimulation. C-Fos expression was used to track neuronal activation.Main result. C-Fos expression was not present in regions impacted by only one high-frequency magnetic field indicating ineffective recruitment of neural activity in non-target regions. In contrast, regions impacted by two fields that interfere to create a low-frequency envelope display a strong increase in c-Fos expression.Significance. Therefore, this magnetic temporal interference solenoid-based system provides a framework to perform further stimulation studies that would investigate the advantages it could bring over conventional TMS systems.

Long-term outcomes of add-on direct renin inhibition in igA nephropathy: a propensity score-matched cohort study.

INTRODUCTION: The long-term clinical outcomes in biopsy proven IgAN patients treated with aliskiren on top of a maximally tolerated dose of ACEi/ARB remain unknown. METHODS: Patients with IgAN treated with a direct renin inhibitor and ACEi/ARB for at least 6 months were compared with a 1:1 propensityscore-matched cohort (including MEST-C score and the 12-months pre-exposure slope of eGFR matching) who received ACEi/ARB without aliskiren exposure to compute the hazard ratio of reaching the primary endpoint of a composite of 40% reduction in eGFR, initiation of KRT and all-cause mortality. Secondary outcome measures included changes in mean UPCR, blood pressure, eGFR, incidence of hyperkalemia and other adverse events during follow-up. RESULTS: After a median follow-up of 2.5 years, 8/36 (22.2%) aliskiren-treated patients and 6/36 (16.7%) control patients reached the primary composite outcome (HR = 1.60; 95% CI 0.52-4.88; P = 0.412). Aliskiren treatment increased the risk of ≥ 40% eGFR decline (HR = 1.60; 95% CI 0.52-4.88; P = 0.412), and hyperkalemia (HR = 8.60; 95% CI 0.99-73.64; P = 0.050). At 10.8 years, renal composite outcome was reached in 69.4% vs 58.3% (HR = 2.16; 95% CI 1.18-3.98; P = 0.013) of patients in the aliskiren and control groups, respectively. The mean UPCR reduction between treatment and control was not statistically different (52.7% vs 42.5%; 95% CI 0.63-2.35; P = 0.556). The mean intergroup difference in eGFR decline over 60 months was 7.75 ± 3.95 ml/min/1.73 m2 greater in the aliskiren group (12.83 vs 5.08; 95% CI - 0.17 to 15.66; P = 0.055). CONCLUSION: Among patients with IgAN, add-on aliskiren was associated with less favorable long-term kidney outcomes despite an initial anti-proteinuric effect.

Adenofibromatous Solitary Fibrous Tumor: An Unusual Morphologic Variant Occurring in the Sinonasal Tract.

BACKGROUND: Solitary fibrous tumor can exhibit a broad morphologic spectrum, such as presence of epithelioid tumor cells, adipose cells and multinucleated giant cells. This report describes an unusual morphologic variant characterized by adenofibromatous features, all occurring in the sinonasal region. METHODS: Four cases of the adenofibromatous variant of solitary fibrous tumor were retrieved from the surgical pathology and consultation files in Queen Elizabeth Hospital, Hong Kong. Histologic examination, immunohistochemical study and reverse-transcription polymerase chain reaction (RT-PCR) were performed. RESULTS: The patients were adults who presented with an obstructive mass of the nasal septum, nasal cavity or nasolacrimal sac. Histologic examination showed a circumscribed biphasic tumor with intermingling of glandular structures and spindle cells, reminiscent of mammary fibroadenoma. Bland-looking spindle cells formed short, irregularly oriented fascicles, admixed with variable amount of collagen fibers. The glandular component comprised ducts and seromucinous acini with a lobular architecture, indicating that it represented exuberant hyperplasia of indigenous glands rather than part of the neoplastic process. Demonstration of CD34 and STAT6 immunoreactivity in the spindle cells and NAB2::STAT6 gene fusion by polymerase chain reaction supports the diagnosis of solitary fibrous tumor. CONCLUSION: This study reports four cases of sinonasal solitary fibrous tumor with adenofibromatous features, furthermore expanding the morphologic spectrum of this tumor.

Development of the Residual Lesion Score for congenital heart surgery: the RAND Delphi methodology.

BACKGROUND AND OBJECTIVE: The Residual Lesion Score is a novel tool for assessing the achievement of surgical objectives in congenital heart surgery based on widely available clinical and echocardiographic characteristics. This article describes the methodology used to develop the Residual Lesion Score from the previously developed Technical Performance Score for five common congenital cardiac procedures using the RAND Delphi methodology. METHODS: A panel of 11 experts from the field of paediatric and congenital cardiology and cardiac surgery, 2 co-chairs, and a consultant were assembled to review and comment on validity and feasibility of measuring the sub-components of intraoperative and discharge Residual Lesion Score for five congenital cardiac procedures. In the first email round, the panel reviewed and commented on the Residual Lesion Score and provided validity and feasibility scores for sub-components of each of the five procedures. In the second in-person round, email comments and scores were reviewed and the Residual Lesion Score revised. The modified Residual Lesion Score was scored independently by each panellist for validity and feasibility and used to develop the "final" Residual Lesion Score. RESULTS: The Residual Lesion Score sub-components with a median validity score of ≥7 and median feasibility score of ≥4 that were scored without disagreement and with low absolute deviation from the median were included in the "final" Residual Lesion Score. CONCLUSION: Using the RAND Delphi methodology, we were able to develop Residual Lesion Score modules for five important congenital cardiac procedures for the Pediatric Heart Network's Residual Lesion Score study.

Intrinsic Plasticity Mechanisms of Repetitive Transcranial Magnetic Stimulation.

Repetitive transcranial magnetic stimulation (rTMS) has become an increasingly popular tool to modulate neural excitability and induce neural plasticity in clinical and preclinical models; however, the physiological mechanisms in which it exerts these effects remain largely unknown. To date, studies have primarily focused on characterizing rTMS-induced changes occurring at the synapse, with little attention given to changes in intrinsic membrane properties. However, accumulating evidence suggests that rTMS may induce its effects, in part, via intrinsic plasticity mechanisms, suggesting a new and potentially complementary understanding of how rTMS alters neural excitability and neural plasticity. In this review, we provide an overview of several intrinsic plasticity mechanisms before reviewing the evidence for rTMS-induced intrinsic plasticity. In addition, we discuss a select number of neurological conditions where rTMS-induced intrinsic plasticity has therapeutic potential before speculating on the temporal relationship between rTMS-induced intrinsic and synaptic plasticity.

Does 3-dimensional facial attractiveness relate to golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles?

BACKGROUND: The established recommendations and guidelines regarding ideal measurements for an attractive face are mostly based on data gathered among Caucasian population. The aim of this study was to examine the relationship between perception of 3-dimensional facial attractiveness and golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles in Hong Kong Chinese. METHODS: Thirty 3-D photographs (15 males and 15 females) were shown to 101 laypersons and 60 patients seeking orthognathic treatment. The photographs were rated based on a 100 mm visual analogue scale (VAS) from 0 (very unattractive) to 100 (very attractive). RESULTS: More than half of the measurements (42/77) in females and thirty-two measurements in males were found to be significantly different from the ideal target value (p < 0.05) upon the comparison of the attractive faces with golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles. Meanwhile, correlation tests between VAS scores and the parameters detected significant results (p < 0.05) in only six ratios, eight angles, one neoclassical canon and one proportion. CONCLUSIONS: Despite several renowned 'ideal' parameters of attractive faces that have been recommended in the literature, only a few of them were found to be significantly correlated with attractive faces in Hong Kong Chinese.

Drastic effects of an inert Pt wire on the redox behavior of the Belousov-Zhabotinsky reaction.

This research investigated responses of the Belousov-Zhabotinsky (BZ) reaction to the presence of a chemically inert Pt wire in solution. Experiments showed that connecting the Pt wire to a neutral ground caused a spontaneous drastic shift in the redox potential and might even induce complex behavior. Characterizations using an unstirred ferriin solution demonstrated the formation of a red colored propagating front at the grounded Pt wire, suggesting the reduction of ferriin to ferroin. Measurements with different combinations of electrodes in both stirred and reaction-diffusion media further confirmed the reduction of BZ metal catalysts at the Pt wire and the accompanying oxidation reaction at the reference electrode. The observed drastic change in redox potential and oscillation waveform can be understood based on the passive reduction reaction at the indicator electrode that is connected to the reference electrode through a potential meter. The obtained influence can be further manipulated by adding a resistor between the Pt wire and the neutral ground, making this convenient perturbation method attractive for the study of redox chemical reaction dynamics.

Rare case of epithelioid hemangioendothelioma in the right innominate vein-An innovative diagnostic approach.

BACKGROUND AND AIMS: Epithelioid hemangioendothelioma is a rare malignant vascular tumor with limited literature. AIMS: We reported an innovative endovascular biopsy of the right innominate vein tumor. MATERIALS AND METHODS: Endovascular suction thrombectomy was performed with multipurpose catheter and constant negative pressure under fluoroscopic guidance. RESULTS: Epithelioid hemangioendothelioma was diagnosed preoperatively and a complete margin-free tumor resection with patch repair of the right innominate vein was achieved via sternotomy. DISCUSSION: Preoperatively diagnosis is usually not available due to lesions' location. Identifying malignant vascular tumors becomes valuable to guide the surgical treatment. CONCLUSIONS: In this case report, this innovative endovascular approach led to a rare preoperative diagnosis of EHE and subsequent margin-free resection.

TRIM33 drives prostate tumor growth by stabilizing androgen receptor from Skp2-mediated degradation.

Androgen receptor (AR) is a master transcription factor that drives prostate cancer (PCa) development and progression. Alterations in the expression or activity of AR coregulators significantly impact the outcome of the disease. Using a proteomics approach, we identified the tripartite motif-containing 33 (TRIM33) as a novel transcriptional coactivator of AR. We demonstrate that TRIM33 facilitates AR chromatin binding to directly regulate a transcription program that promotes PCa progression. TRIM33 further stabilizes AR by protecting it from Skp2-mediated ubiquitination and proteasomal degradation. We also show that TRIM33 is essential for PCa tumor growth by avoiding cell-cycle arrest and apoptosis, and TRIM33 knockdown sensitizes PCa cells to AR antagonists. In clinical analyses, we find TRIM33 upregulated in multiple PCa patient cohorts. Finally, we uncover an AR-TRIM33-coactivated gene signature highly expressed in PCa tumors and predict disease recurrence. Overall, our results reveal that TRIM33 is an oncogenic AR coactivator in PCa and a potential therapeutic target for PCa treatment.

Escargot controls somatic stem cell maintenance through the attenuation of the insulin receptor pathway in Drosophila.

Adult stem cells coordinate intrinsic and extrinsic, local and systemic, cues to maintain the proper balance between self-renewal and differentiation. However, the precise mechanisms stem cells use to integrate these signals remain elusive. Here, we show that Escargot (Esg), a member of the Snail family of transcription factors, regulates the maintenance of somatic cyst stem cells (CySCs) in the Drosophila testis by attenuating the activity of the pro-differentiation insulin receptor (InR) pathway. Esg positively regulates the expression of an antagonist of insulin signaling, ImpL2, while also attenuating the expression of InR. Furthermore, Esg-mediated repression of the InR pathway is required to suppress CySC loss in response to starvation. Given the conservation of Snail-family transcription factors, characterizing the mechanisms by which Esg regulates cell-fate decisions during homeostasis and a decline in nutrient availability is likely to provide insight into the metabolic regulation of stem cell behavior in other tissues and organisms.

Facial profile study using 3-dimensional photographs to assess esthetic preferences of Hong Kong Chinese orthognathic patients and laypersons.

INTRODUCTION: This study was conducted to investigate and compare esthetic perceptions of different facial profiles among Hong Kong Chinese laypersons and patients scheduled for orthognathic treatment. METHODS: Two sets of 3-dimensional facial photographs (1 male and 1 female) each comprised 7 images that showed different dentoskeletal relations (ie, Class I, bimaxillary protrusion, bimaxillary retrusion, maxillary protrusion, maxillary retrusion, mandibular protrusion, and mandibular retrusion). The sets of photographs were shown to 101 laypersons (age, 28.87 ± 6.22 years) and 60 patients seeking orthognathic treatment (age, 27.12 ± 6.07 years). They rated their esthetic perceptions of the photographs on the basis of a 100 mm visual analog scale (VAS) from 0 (very unattractive) to 100 (very attractive). RESULTS: The dentoskeletal Class I facial profile was ranked as the most attractive profile. Female orthognathic judges selected the retrusive maxilla while male orthognathic judges and male and female laypersons ranked the mandibular protrusion profile as the least attractive profile for both females and males. A bimaxillary protrusive female profile was viewed as more attractive by the orthognathic male (P = 0.006) and female (P = 0.006) judges, compared with female layperson judges. After adjustment for age, no statistically significant interaction between sex and judges (P >0.10) for all VAS scores were detected. For the female bimaxillary protrusive profile, orthognathic patient judges assigned a mean VAS score of 9.174 points higher than layperson judges (95% confidence interval, 3.11-15.24; P = 0.003). CONCLUSION: Dentoskeletal Class I facial profile was generally considered the most attractive profile in both sexes; male and female orthognathic patients preferred a bimaxillary protrusive female profile. A concave facial profile was perceived as least attractive in both sexes.

Patient pIgR-enriched extracellular vesicles drive cancer stemness, tumorigenesis and metastasis in hepatocellular carcinoma.

BACKGROUND & AIMS: Extracellular vesicles (EVs) play a pivotal role in connecting tumor cells with their local and distant microenvironments. Herein, we aimed to understand the role (on a molecular basis) patient-derived EVs play in modulating cancer stemness and tumorigenesis in the context of hepatocellular carcinoma (HCC). METHODS: EVs from patient sera were isolated, quantified and characterized. The EVs were vigorously tested, both in vitro and in vivo, through various functional assays. Proteomic analysis was performed to identify the functional components of EVs. The presence and level of polymeric immunoglobulin receptor (pIgR) in circulating EVs and tumor and non-tumorous tissues of patients with HCC were determined by ELISA, immunoblotting, immunohistochemistry and quantitative PCR. The functional role and underlying mechanism of EVs with enhanced pIgR expression were elucidated. Blockade of EV-pIgR with neutralizing antibody was performed in nude mice implanted with patient-derived tumor xenografts (PDTXs). RESULTS: Circulating EVs from patients with late-stage HCC (L-HCC) had significantly elevated pIgR expression compared to the EVs released by control individuals. The augmenting effect of L-HCC-EVs on cancer stemness and tumorigenesis was hindered by an anti-pIgR antibody. EVs enriched with pIgR consistently promoted cancer stemness and cancerous phenotypes in recipient cells. Mechanistically, EV-pIgR-induced cancer aggressiveness was abrogated by Akt and ß-catenin inhibitors, confirming that the role of EV-pIgR depends on the activation of the PDK1/Akt/GSK3ß/ß-catenin signaling axis. Furthermore, an anti-pIgR neutralizing antibody attenuated tumor growth in mice implanted with PDTXs. CONCLUSIONS: This study illustrates a previously unknown role of EV-pIgR in regulating cancer stemness and aggressiveness: EV-pIgR activates PDK1/Akt/GSK3ß/ß-catenin signaling cascades. The blockade of the intercellular communication mediated by EV-pIgR in the tumor microenvironment may provide a new therapeutic strategy for patients with cancer. LAY SUMMARY: The World Health Organization estimates that more than 1 million patients will die from liver cancer, mostly hepatocellular carcinoma (HCC), in 2030. Understanding the underlying mechanism by which HCC acquires aggressive attributes is crucial to improving the diagnosis and treatment of patients. Herein, we demonstrated that nanometer-sized extracellular vesicles released by tumors promote cancer stemness and tumorigenesis. Within these oncogenic vesicles, we identified a key component that functions as a potent modulator of cancer aggressiveness. By inhibiting this functional component of EVs using a neutralizing antibody, tumor growth was profoundly attenuated in mice. This hints at a potentially effective therapeutic alternative for patients with cancer.

Subthreshold repetitive transcranial magnetic stimulation drives structural synaptic plasticity in the young and aged motor cortex.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool commonly used to drive neural plasticity in the young adult and aged brain. Recent data from mouse models have shown that even at subthreshold intensities (0.12 T), rTMS can drive neuronal and glial plasticity in the motor cortex. However, the physiological mechanisms underlying subthreshold rTMS induced plasticity and whether these are altered with normal ageing are unclear. OBJECTIVE: To assess the effect of subthreshold rTMS, using the intermittent theta burst stimulation (iTBS) protocol on structural synaptic plasticity in the mouse motor cortex of young and aged mice. METHODS: Longitudinal in vivo 2-photon microscopy was used to measure changes to the structural plasticity of pyramidal neuron dendritic spines in the motor cortex following a single train of subthreshold rTMS (in young adult and aged animals) or the same rTMS train administered on 4 consecutive days (in young adult animals only). Data were analysed with Bayesian hierarchical generalized linear regression models and interpreted with the aid of Bayes Factors (BF). RESULTS: We found strong evidence (BF > 10) that subthreshold rTMS altered the rate of dendritic spine losses and gains, dependent on the number of stimulation sessions and that a single session of subthreshold rTMS was effective in driving structural synaptic plasticity in both young adult and aged mice. CONCLUSION: These findings provide further evidence that rTMS drives synaptic plasticity in the brain and uncovers structural synaptic plasticity as a key mechanism of subthreshold rTMS induced plasticity.

TPI1-reduced extracellular vesicles mediated by Rab20 downregulation promotes aerobic glycolysis to drive hepatocarcinogenesis.

Rab GTPases are major mediators that ensure the proper spatiotemporal regulation of intracellular trafficking. Functional impairment and altered expression of Rab proteins have been revealed in various human cancers. There is an emerging evidence about the role of Rab proteins in the biogenesis of extracellular vesicles (EVs). In hepatocellular carcinoma (HCC), using RNA sequencing comparing expression profiles of adjacent non-tumorous tissues and HCC, Rab20 is identified to be the most frequently downregulated Rab member in HCC. Functionally, restoration of Rab20 in metastatic HCC cells results in the release of EVs with a diminished activity to promote cell growth, motility and metastasis. Conversely, EVs released from normal liver cells with Rab20 knockdown loses suppressive effect on HCC cell growth and motility. Proteomic profiling revealed the level of triosephosphate isomerase 1 (TPI1), a glycolytic enzyme, in EVs to be positively associated with Rab20 expression of the releasing cells. TPI1 targeted to be expressed in EVs released by Rab20 knockdown cells compromises the oncogenic activity of EVs. Besides, EVs released by TPI1 knockdown cells recapitulates the promoting effect of EVs derived from HCC cells with Rab20 underexpression. Aerobic glycolysis is beneficial to the survival and proliferation of tumour cells. Here, we observed that the enhanced cell growth and motility are driven by the enhanced aerobic glycolysis induced by EVs with reduced TPI1. The addition of glycolytic inhibitor blocks the promoting effect of EVs with reduced TPI1. Taken together, our study provides a mechanistic link among tumour cell-derived EVs and glucose metabolism in HCC with Rab20 deregulation.

Suppression of ACADM-Mediated Fatty Acid Oxidation Promotes Hepatocellular Carcinoma via Aberrant CAV1/SREBP1 Signaling.

Lipid accumulation exacerbates tumor development, as it fuels the proliferative growth of cancer cells. The role of medium-chain acyl-CoA dehydrogenase (ACADM), an enzyme that catalyzes the first step of mitochondrial fatty acid oxidation, in tumor biology remains elusive. Therefore, investigating its mode of dysregulation can shed light on metabolic dependencies in cancer development. In hepatocellular carcinoma (HCC), ACADM was significantly underexpressed, correlating with several aggressive clinicopathologic features observed in patients. Functionally, suppression of ACADM promoted HCC cell motility with elevated triglyceride, phospholipid, and cellular lipid droplet levels, indicating the tumor suppressive ability of ACADM in HCC. Sterol regulatory element-binding protein-1 (SREBP1) was identified as a negative transcriptional regulator of ACADM. Subsequently, high levels of caveolin-1 (CAV1) were observed to inhibit fatty acid oxidation, which revealed its role in regulating lipid metabolism. CAV1 expression negatively correlated with ACADM and its upregulation enhanced nuclear accumulation of SREBP1, resulting in suppressed ACADM activity and contributing to increased HCC cell aggressiveness. Administration of an SREBP1 inhibitor in combination with sorafenib elicited a synergistic antitumor effect and significantly reduced HCC tumor growth in vivo. These findings indicate that deregulation of fatty acid oxidation mediated by the CAV1/SREBP1/ACADM axis results in HCC progression, which implicates targeting fatty acid metabolism to improve HCC treatment. SIGNIFICANCE: This study identifies tumor suppressive effects of ACADM in hepatocellular carcinoma and suggests promotion of ß-oxidation to diminish fatty acid availability to cancer cells could be used as a therapeutic strategy.