LINC00998-encoded micropeptide SMIM30 promotes the G1/S transition of cell cycle by regulating cytosolic calcium level

The biological functions of short open reading frame (sORF)-encoded micropeptides remain largely unknown. Here, we report that LINC00998, a previously annotated lncRNA, was upregulated in multiple cancer types and the sORF on LINC00998 encoded a micropeptide named SMIM30. SMIM30 was localized in the membranes of the endoplasmic reticulum (ER) and mitochondria. Silencing SMIM30 inhibited the proliferation of hepatoma cells in vitro and suppressed the growth of tumor xenografts and N-nitrosodiethylamine-induced hepatoma. Overexpression of the 5'UTR-sORF sequence of LINC00998, encoding wild-type SMIM30, enhanced tumor cell growth, but this was abolished when a premature stop codon was introduced into the sORF via single-base deletion. Gain- and loss-of-function studies revealed that SMIM30 peptide but not LINC00998 reduced cytosolic calcium level, increased CDK4, cyclin E2, phosphorylated-Rb and E2F1, and promoted the G1/S phase transition and cell proliferation. The effect of SMIM30 silencing was attenuated by a calcium chelator or the agonist of sarco/endoplasmic reticulum calcium ATPase (SERCA) pump. These findings suggest a novel function of micropeptide SMIM30 in promoting G1/S transition and cell proliferation by enhancing SERCA activity and reducing cytosolic calcium level.

A long non-coding RNA-based signature predicts early recurrence in hepatocellular carcinoma

BACKGROUND

Early recurrence is the main obstacle for long-term survival of hepatocellular carcinoma (HCC) patients after curative resection.

OBJECTIVE

We aimed to develop a long non-coding RNA (lncRNA) based signature to predict early recurrence.

METHODS

Using bioinformatics analysis and quantitative reverse transcription PCR (RT-qPCR), we screened for lncRNA candidates that were abnormally expressed in HCC. The expression levels of candidate lncRNAs were analyzed in HCC tissues from 160 patients who underwent curative resection, and a risk model for the prediction of recurrence within 1 year (early recurrence) of HCCs was constructed with linear support vector machine (SVM).

RESULTS

A lncRNA-based classifier (Clnc), which contained nine differentially expressed lncRNAs including AF339810, AK026286, BC020899, HEIH, HULC, MALAT1, PVT1, uc003fpg, and ZFAS1 was constructed. In the test set, this classifier reliably predicted early recurrence (AUC, 0.675; sensitivity, 72.0%; specificity, 63.1%) with an odds ratio of 4.390 (95% CI, 2.120-9.090). Clnc showed higher accuracy than traditional clinical features, including tumor size, portal vein tumor thrombus (PVTT) in predicting early recurrence (AUC, 0.675 vs 0.523 vs 0.541), and had much higher sensitivity than Barcelona Clinical Liver Cancer (BCLC; 72.0% vs 50.0%), albeit their AUCs were comparable (0.675 vs 0.678). Moreover, combining Clnc with BCLC significantly increased the AUC, compared with Clnc or BCLC alone in predicting early recurrence (all P< 0.05). Finally, logistic and Cox regression analysis suggested that Clnc was an independent prognostic factor and associated with the early recurrence and recurrence-free survival of HCC patients after resection, respectively (all P= 0.001).

CONCLUSIONS

Our lncRNA-based classifier Clnc can predict early recurrence of patients undergoing surgical resection of HCC.

LncRNA SNHG17 interacts with LRPPRC to stabilize c-Myc protein and promote G1/S transition and cell proliferation

Oncogenic c-Myc is a master regulator of G1/S transition. Long non-coding RNAs (lncRNAs) emerge as new regulators of various cell activities. Here, we found that lncRNA SnoRNA Host Gene 17 (SNHG17) was elevated at the early G1-phase of cell cycle. Both gain- and loss-of function studies disclosed that SNHG17 increased c-Myc protein level, accelerated G1/S transition and cell proliferation, and consequently promoted tumor cell growth in vitro and in vivo. Mechanistically, the 1-150-nt of SNHG17 physically interacted with the 1035-1369-aa of leucine rich pentatricopeptide repeat containing (LRPPRC) protein, and disrupting this interaction abrogated the promoting role of SNHG17 in c-Myc expression, G1/S transition, and cell proliferation. The effect of SNHG17 in stimulating cell proliferation was attenuated by silencing c-Myc or LRPPRC. Furthermore, silencing SNHG17 or LRPPRC increased the level of ubiquitylated c-Myc and reduced the stability of c-Myc protein. Analysis of human hepatocellular carcinoma (HCC) tissues revealed that SNHG17, LRPPRC, and c-Myc were significantly upregulated in HCC, and they showed a positive correlation with each other. High level of SNHG17 or LRPPRC was associated with worse survival of HCC patients. These data suggest that SNHG17 may inhibit c-Myc ubiquitination and thus enhance c-Myc level and facilitate proliferation by interacting with LRPPRC. Our findings identify a novel SNHG17-LRPPRC-c-Myc regulatory axis and elucidate its roles in G1/S transition and tumor growth, which may provide potential targets for cancer therapy.

Functional long non-coding RNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent human malignancy with high morbidity worldwide. Hepatocarcinogenesis is a complex multistep process, and its underlying molecular mechanisms remain largely unknown. Recently, long non-coding RNAs (lncRNAs), a class of newly discovered molecules, have been revealed as essential regulators in the development of HCC. HCC-associated lncRNAs affect multiple malignant phenotypes by modulating gene expression or protein activity. Moreover, the dysregulation of lncRNAs in the liver is also associated with diseases predisposing to HCC, such as chronic viral infection, nonalcoholic steatohepatitis, and liver fibrosis/cirrhosis. A deeper understanding of the lncRNA regulatory network in the multistep processes of HCC development will provide new insights into the diagnosis and treatment of HCC. In this review, we introduce the biogenesis and function of lncRNAs and summarize recent knowledge on how lncRNAs regulate the malignant hallmarks of HCC, such as uncontrolled cell proliferation, resistance to cell death, metabolic reprogramming, immune escape, angiogenesis, and metastasis. We also review emerging insights into the role of lncRNAs in HCC-associated liver diseases. Finally, we discuss the potential applications of lncRNAs as early diagnostic biomarkers and therapeutic targets.

Role of liquid-liquid phase separation in cell physiology and diseases

There are many liquid-like membraneless compartments in eukaryotic cells. Recent studies have shown that these membraneless compartments are formed through liquid-liquid phase separation (LLPS), driven by proteins, nucleic acids, and other biomacromolecules. LLPS is involved in different cell activities such as regulation of gene expression, signal transduction, stress response and so on. It is shown that dysregulation of LLPS is associated with neurodegenerative disease and cancer. This review discusses the formation and regulation of liquid-liquid separation and their roles in cell physiology and diseases.

LncRNA GOLGA2P10 is induced by PERK/ATF4/CHOP signaling and protects tumor cells from ER stress-induced apoptosis by regulating Bcl-2 family members

Elevated endoplasmic reticulum (ER) stress is frequently observed in cancers, whereas sustained ER stress may trigger apoptosis. How cancer cells escape from ER stress-induced apoptosis remain unclear. Here, we found that a pseudogene-derived lncRNA, Golgin A2 pseudogene 10 (GOLGA2P10), was frequently upregulated in HCC tissues and significantly elevated in hepatoma cells treated with ER stress inducers, such as tunicamycin and thapsigargin. Higher GOLGA2P10 level was correlated with shorter recurrence-free survival of HCC patients. Upon ER stress, CHOP directly bound to the promoter of GOLGA2P10 and induced its transcription via the PERK/ATF4/CHOP pathway. Interestingly, the ER stress inducer-stimulated apoptosis was promoted by silencing GOLGA2P10 but was antagonized by overexpressing GOLGA2P10. Both gain- and loss-of-function analyses disclosed that GOLGA2P10 increased BCL-xL protein level, promoted BAD phosphorylation, and conferred tumor cells with resistance to ER stress-induced apoptosis. Moreover, BCL-xL overexpression or BAD knockdown abrogated the apoptosis-promoting effect of GOLGA2P10 silencing. Consistently, the Ser75Ala mutation in BAD, which caused phosphorylation-resistance, further enhanced the promoting effect of BAD in tunicamycin-induced apoptosis. These results suggest that ER stress induces GOLGA2P10 transcription through the PERK/ATF4/CHOP pathway, and upregulation of GOLGA2P10 protects tumor cells from the cytotoxic effect of persistent ER stress in tumor microenvironment by regulating Bcl-2 family members, which highlight GOLGA2P10 as a potential target for anticancer therapy.

[Characteristics of Phosphorus Adsorption in Aqueous Solution By Ca/Mg-Loaded Biogas Residue Biochar]

In this study, we synthesized Ca/Mg biochar sorbents (CMZZs) by pyrolysis of biogas residue (ZZs) impregnated with calcium chloride and magnesium chloride and investigated their potential to adsorb P from water. The results showed that the content of calcium and magnesium in the modified biochar was 1.3 and 15.4 times, respectively, what they were before the modification. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) patterns showed that the type of chemical functional groups on the surface of biochar had not changed, but several new peaks appeared, indicating that Mg (OH)₂ and MgO might be present on the surface of the CMZZs. The biochar equilibrium data were well described by the Freundlich model, and the adsorption reached equilibrium after 100 min. The adsorption kinetics followed a pseudo-second-order model, and the maximum adsorption capacity of the CMZZs was 76.92 mg·g^-1 when the pH was 9 and the temperature 303 K. The results revealed that a soaking method can effectively load Ca²⁺ and Mg²⁺ onto the surface of ZZ, and CMZZs offer a promising adsorbent for P removal with a high adsorption capacity for P from wastewater.

Emerging landscape of short open reading frame-encoded peptides

Short open reading frames (sORFs) are a common feature of genomes of human and other species, but their coding potential remains unknown. Innovations in proteomics and high-throughput analyses of translation start sites have resulted in the identification of hundreds of putative coding sORFs, and some of them have been verified to be able to translated into short peptides (<100 amino acids). Moreover, recent findings reveal their diverse functions in various biological processes including development and differentiation. This review discusses the translation, identification and biological function of short peptides.

Magnesium-doped zinc oxide electrochemically grown on fluorine-doped tin oxide substrate

Nanostructures of magnesium (Mg) doped Zinc oxide (ZnO) were successfully deposited on conducting fluorine-doped tin oxide (FTO) coated glass plates by cathodic electrochemical deposition method at different potentials and temperature conditions. The deposited samples were characterized by XRD and SEM techniques to confirm their structures, morphologies and optical properties. These measurements show that Mg doped ZnO has a wurtzite structure and that the strongest intensity of the (002) peak is found at 60 degrees C and -1.0 V. Tunable transmittance of Mg doped ZnO has a band gap energy from 3.45 eV to 3.82 eV, which is the direct evidence of doping.

Promoter polymorphism of MRP1 associated with reduced survival in hepatocellular carcinoma

AIM: To investigate the effect of the G-1666A polymorphism in the multidrug resistance related protein-1 (MRP1) on outcome of hepatocellular carcinoma (HCC).

METHODS: A cohort of 162 patients with surgically resected HCC who received no postsurgical treatment until relapse was studied. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism analysis. Electrophoretic mobility shift assay (EMSA) was used to evaluate the influence of the G-1666A polymorphism on the binding affinity of the MRP1 promoter with its putative transcription factors.

RESULTS: Kaplan-Meier analysis showed that patients with GG homologues had a reduced 4-year disease-free survival compared with those carrying at least one A allele (P = 0.011). Multivariate Cox regression analysis indicated that the -1666GG genotype represented an independent predictor of poorer disease-free survival [hazard ratio (HR) = 3.067, 95% confidence interval (CI): 1.587-5.952, P = 0.001], and this trend became worse in men (HR = 3.154, 95% CI: 1.604-6.201, P = 0.001). A similar association was also observed between 4-year overall survival and the polymorphism in men (HR = 3.342, 95% CI: 1.474-7.576, P = 0.004). Moreover, EMSA suggested that the G allele had a stronger binding affinity to nuclear proteins.

CONCLUSION: The MRP1 -1666GG genotype predicted a worse outcome and was an independent predictor of poor survival in patients with HCC from Southeast China.

Mechanistic evidence and efficiency of the Cr(VI) reduction in water by different sources of zerovalent irons

The objective of this research was to assess the mechanism and effectiveness of the zerovalent iron (ZVI) to remediate the Cr(VI) contaminated water. The mechanism of Cr(VI) reduction by ZVI was evaluated by characterising surface properties and chemical compositions of Fe and Cr products using SEM-EDS, XRD and XPS analyses. The effectiveness of ZVI in Cr(VI) reduction was assessed by the luminescent bacteria (Photobacterium Phosphoreum). The Cr(VI) was reduced to Cr(III), when the reactive Fe(o) was oxidised to Fe(II, III), showing the presence of Fe2O3, (Fe-Cr)2O3 and FeOOH. The SEM-EDS analysis showed that ZVI with a higher reducing capacity was more subject to changes of surface and morphological properties due to ionisation of ZVI. The Cr and Fe in precipitates subsisted exclusively in the Cr(III) or Fe(III) states with the respective forms of Cr(OH)3 or Cr2O3 and FeOOH or Fe2O3. Electrons produced from ZVI oxidation reduced Cr(VI) to Cr(III), thus resultantly Cr(III) precipitated or co-precipitated with Fe(III) to form Fe(III)-Cr(III) hydroxide or Fe(III)-Cr(III) oxyhydroxide. Toxicity of water reacted with ZVI was significantly lower than that of the untreated water.

A case of extragenital lichen sclerosus following Blaschko's lines

Extragenital lichen sclerosus is most common on the neck, shoulders, and upper portion of the trunk. A 20-year-old Korean man had asymptomatic, well-demarcated, linear violaceous plaques on the left lateral chest, in a pattern corresponding to the lines of Blaschko. We describe a case with a pattern of extragenital lichen sclerosus following Blaschko's lines.

Screening of hexavalent chromium biosorbent from marine algae

A highly chromate-selective biosorbent with high adsorption capacity was found by examining the chromate adsorption capacities of 48 species of red, brown, or green marine algae sampled from the east coast of Korea. As a result of screening, a red marine alga showed excellent adsorption characteristics. It was identified as Pachymeniopsis sp. The timing of the sampling of Pachymeniopsis sp. did not affect the adsorption capacity of the alga but the optimum period for mass collection was April-May. The alga also showed high selectivity for chromate and its adsorption capacity for other heavy metal ions such as cadmium and manganese was relatively low. An investigation of the adsorption isotherm of Pachymeniopsis sp. as a dried powder for chromate adsorption at 25 degrees C showed Langmuir-type dependence. The maximum chromate adsorption capacity of the selected alga was about 225 mg/g. The desorption of adsorbed chromate from Pachymeniopsis sp. was done by treating samples with 1 N NaOH. It was confirmed that ion exchange type adsorption was observed with anion exchangers but not with cation exchangers. Therefore it is believed that the chromate adsorption is based on the anionic exchange of Pachymeniopsis sp.

Screening of hexavalent chromium biosorbent for marine algae

A high-chromate-selective biosorbent with high adsorption capacity was sought by examining the chromate adsorption capacities of 48 species of red, brown, or green marine algae sampled from the east coast of Korea. Screening showed a red marine alga to have the most excellent adsorption characteristics among them, and it was identified as Pachymeniopsis sp. The period at which Pachymeniopsis sp. was sampled did not affect the adsorption capacity of the alga, but the optimum period for mass collection was April to May. The alga also showed high selectivity for chromate since its adsorption capacity for other heavy metal ions such as cadmium and manganese ions was relatively low. An investigation of the adsorption isotherm of dried powder of Pachymeniopsis sp. for chromate adsorption at 25 degrees C showed a Langmuir-type dependence. The maximum chromate adsorption capacity of the selected alga was about 225 mg/g. Desorption of the adsorbed chromate from Pachymeniopsis sp. was done by treating the sample with 1 N NaOH. It was confirmed that ion exchange type adsorption was observed with an anion exchanger but not with a cation exchanger. It is therefore believed that the chromate adsorption is based on anionic exchange of Pachymeniopsis sp.