HMG1 Gene Research Articles

Initial Results in a Phase 1b Trial of PB-04 in Sickle Cell Disease Demonstrate Fetal Hemoglobin Induction, Additive Activity with Hydroxyurea, and Improved Red Blood Cell Sickling Parameters

Extensive evidence has shown fetal hemoglobin (HbF) is a major modulator of sickle cell disease (SCD) phenotype. Clinical benefit with any increment of HbF was shown in the NIH-sponsored Natural History Study and the Multicenter Study of Hydroxyurea (HU), with mean HbF increases of 3.6% above baseline (BL), to improve survival, reduce painful vaso-occlusive crises, and recently stroke prevention and improved cardiac and neurocognitive function with HU are reported. As some patients do not tolerate optimal HU doses due to cytopenias, additional inducers suitable for combined use are desirable. Proportions of F-cells and HbF-quantity/cell have been cited as important. PB-04, a repurposed drug with a well-known safety profile, is an oral fetal globin stimulant identified in high throughput screening, which suppresses 4 repressors of the HMG gene promoter, ( BCL-11A, LSD-1, HDAC-3, KLF-1). PB-04 induces fetal globin in nonhuman primates, transgenic mice, with additive effect when combined with HU in SCD erythroid progenitors, and was shown to reduce infarcts in multiple organs with preserved splenic function in transgenic sickle mice. An ongoing Phase 1b trial in beta thalassemia intermedia (BTI) ( NCT04432623) of 3 doses (1,3, or 5 mg/kg QD) given 3 (TIW) or 5 times/week (Wk) for 12 or 24 Wks in 18 courses in 10 subjects demonstrates a favorable safety profile, dose-proportional PK with 5 >3 mg/kg doses and 5 >3 doses/Wk, Median fold-increases from baseline (BL) in F-cells of 4.4x BL (range 2.3-7x), 2.8x F-reticulocytes (1.6-14.8x), and 6.5x (range 3-11x) increases in mean fluorescence intensity (MFI, representing amount of HbF/RBC). Mean increases in % HbF were 6.5%. Evaluation of PB-04 has now begun in 7 subjects with SCD, 19-51 yrs; 3 were receiving HU with HbF responses (12-22%). Adverse events, F-cells, F-reticulocytes, MFI (amount of HbF/RBC or HbF/reticulocyte) by FACS and ImageStream Analysis and % HbF are assessed Q 4 wks; flow adhesion of whole blood to VCAM-1 (FA-WB-VCAM) and sickling kinetics are assessed q 12 wks. In 4 subjects on 3 mg/kg QD TIW for 24 wks, changes observed from BL values included mean increases of 6% F-cells and 27% F-reticulocytes (2-fold) . In 3 ongoing subjects receiving 5 mg/kg QD TIW for 12 wks mean changes above BL are currently 13% F-cells, 15% F-reticulocytes; HbF/cell or HbF/reticulocyte have increased up to 10-fold. Mean % HbF has increased above HU effects in 2/3 pts on the second dose by 5-12.6% (mean 8.8%), producing 81-95% F-cells, and 35-38% HbF. Decline in FA-WB-VCAM) was observed ± HU and with both doses in 3 subjects. Correlation of HbF quantity/cell with RBC survival and sickling dynamics is being explored. These early results with not-yet-optimized doses of PB-04 suggest additive activity with HU, producing significant HbF and F-cell levels, and support further PK-optimized studies in patients with SCD.

Network Analysis Reveals the Molecular Bases of Statin Pleiotropy That Vary with Genetic Background.

Many approved drugs are pleiotropic: for example, statins, whose main cholesterol-lowering activity is complemented by anticancer and prodiabetogenic mechanisms involving poorly characterized genetic interaction networks. We investigated these using the Saccharomyces cerevisiae genetic model, where most genetic interactions known are limited to the statin-sensitive S288C genetic background. We therefore broadened our approach by investigating gene interactions to include two statin-resistant genetic backgrounds: UWOPS87-2421 and Y55. Networks were functionally focused by selection of HMG1 and BTS1 mevalonate pathway genes for detection of genetic interactions. Networks, multilayered by genetic background, were analyzed for key genes using network centrality (degree, betweenness, and closeness), pathway enrichment, functional community modules, and Gene Ontology. Specifically, we found modification genes related to dysregulated endocytosis and autophagic cell death. To translate results to human cells, human orthologues were searched for other drug targets, thus identifying candidates for synergistic anticancer bioactivity. IMPORTANCE Atorvastatin is a highly successful drug prescribed to lower cholesterol and prevent cardiovascular disease in millions of people. Though much of its effect comes from inhibiting a key enzyme in the cholesterol biosynthetic pathway, genes in this pathway interact with genes in other pathways, resulting in 15% of patients suffering painful muscular side effects and 50% having inadequate responses. Such multigenic complexity may be unraveled using gene networks assembled from overlapping pairs of genes that complement each other. We used the unique power of yeast genetics to construct genome-wide networks specific to atorvastatin bioactivity in three genetic backgrounds to represent the genetic variation and varying response to atorvastatin in human individuals. We then used algorithms to identify key genes and their associated FDA-approved drugs in the networks, which resulted in the distinction of drugs that may synergistically enhance the known anticancer activity of atorvastatin.

A Whole Genome Sequencing-Based Approach to Track down Genomic Variants in Itraconazole-Resistant Species of Aspergillus from Iran.

The antifungal resistance in non-fumigatus Aspergillus spp., as well as Aspergillus fumigatus, poses a major therapeutic challenge which affects the entire healthcare community. Mutation occurrence of cyp51 gene paralogs is the major cause of azole resistance in Aspergillus spp. To obtain a full map of genomic changes, an accurate scan of the entire length of the Aspergillus genome is necessary. In this study, using whole genome sequencing (WGS) technique, we evaluated the mutation in cyp51A, cyp51B, Cdr1B, AtrR, Hmg1, HapE and FfmA genes in different clinical isolates of Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Aspergillus welwitschiae and Aspergillus terreus which responded to minimum inhibitory concentrations of itraconazole above 16 µg mL−1. We found different nonsynonymous mutations in the cyp51A, cyp51B, Cdr1B, AtrR, Hmg1, HapE and FfmA gene loci. According to our findings, Aspergillus species isolated from different parts of the world may represent different pattern of resistance mechanisms which may be revealed by WGS.

P039 Cross-resistance to clinical and agricultural azoles among Aspergillus fumigatus strains isolated from humans and environment in Italy

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesIn Italy, a prevalence of 16.9% of resistance to clinical azoles was observed among Aspergillus fumigatus isolates from an agricultural environment. This spread of azole-resistance is attributed to the widespread use of 14a-demethylase inhibitors (DMIs).The aims of the present study were to investigate: the DMIs resistance in Italian A. fumigatus strains of clinical and environmental origin, both susceptible and resistant to clinical azoles; the molecular mechanism of resistance in strains susceptible to clinical azoles but resistant to at least one of the tested DMIs; the in vitro DMI resistance induced by prolonged exposure to DMIs in susceptible clinical and environmental strains, and the molecular mechanism of resistance.MethodsA total of 54 A. fumigatus strains were selected: 23 susceptible to clinical azoles (CAS) and 31 resistant (CAR) with and without mutations in the CYP51A gene (TR34/L98H, F219I, G54R, G54E, D269Y, M220I, or F46Y/M172V/N248T/D255E/E427K). Antifungal susceptibility testing was performed for 8 DMIs (tebuconazole, epoxiconazole, difenoconazole, propiconazole, tetraconazole, flusilazole, fenbuconazole, and prochloraz) using broth microdilution method according to EUCAST and CLSI methods. Mutations in CYP51A, CYP51B, and HMG1 genes were investigated in CAS with DMI high MIC values. In vitro induction of resistance was performed using the 8 DMIs on 11 (6 clinical and 5 environmental) A. fumigatus strains susceptible both to clinical azoles and DMIs. A suspension of 106 conidia was inoculated on glucose-yeast extract-peptone agar plates containing different DMIs at different concentrations and incubated at 37°C for 72 h for six repeated passages.ResultsComparable results were obtained using EUCAST and CLSI methods.Resistance (MIC ≥16) to tetraconazole and fenbuconazole was observed in 100% of isolates, both CAR and CAS. On the contrary, a statistically significant difference in tebuconazole, epoxiconazole, difenoconazole, propiconazole, and flusilazole MICs between CAR strains and CAS strains was observed with higher geometric means (GM) in CAR (range 4.9-9.3 mg/L) than in CAS (1.5-2.7 mg/L) strains. Prochloraz showed the lowest GMs: 0.6 and 0.25 mg/L in CAR and CAS strains, respectively.A significant difference of the GMs for all the DMIs tested, except prochloraz, was observed between the isolates harboring a TR34/L98H or a M220I mutation (GM range 10.4-16 mg/L) and those with other CYP51A mutations (GM range 1-4.6 mg/L).In the CAS showing high DMI MICs, the absence of CYP51A mutations was confirmed, while a synonymous mutation P394P, was identified in CYP51B. No mutations in HMG1 gene were found.In the induction tests, the prolonged exposure to DMIs showed an induced phenotypic resistance of 100% (11/11 isolates) for epoxiconazole, of 72.7% (8/11) for propiconazole, of 54% (6/11) for tebuconazole and difenoconazole, and of 9.1% (1/11) for prochloraz.Molecular analysis to understand if the phenotypic resistance corresponds to induced mutations in CYP51A, CYP51B, and HMG1 genes is in progress.ConclusionsPreliminary results confirm cross-resistance between clinical azoles and DMIs, with MIC differences between CAR and CAS and between strains with different mutations in the CYP51A gene. Furthermore, the ability of DMIs to induce resistance in vitro was highlighted.

P059 The overexpression of efflux pump gene cdr1B resulting in voriconazole- and isavuconazole- resistance in Aspergillus fumigatus recovered from a patient with chronic pulmonary aspergillosis in China

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesTriazole resistance in the pathogenic Aspergillus fumigatus has been increasing worldwide, posing a growing therapeutic challenge. To date, triazole resistance in clinical isolates of A. fumigatus causing pulmonary aspergillosis has been mainly attributed to the mutations in the cyp51A gene or its promoter, followed by mutations in cyp51B and hmg1 gene encoding 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. From chronic pulmonary aspergillosis (CPA) patient, we isolated a strain of A. fumigatus (BMU10672) with resistance to voriconazole (VRC) and isavuconazole (ISZ), which was caused by overexpression of efflux pump Cdr1B.MethodsAntifungal susceptibility testing of the isolate of A. fumigatus BMU10672 was performed using the broth microdilution method (CLSI M38-A3), E-test and disk diffusion method. The promoter region and open reading frame of the cyp51A, cyp51B, and hmg1 gene were amplified and sequenced. Then, the expression levels of cyp51A, cyp51B, and efflux pump gene cdr1B with or without being exposed to VRC or ISZ were quantified using real-time PCR, compared with triazole-susceptible A. fumigatus Af293. And the function of efflux pump Cdr1B was tested by efflux pump substrate (Nile red) accumulation assay and efflux pump inhibitor (FK520) assay.ResultsThe minimum inhibitory concentration (MIC) of itraconazole (ITC), VRC, posaconazole (POS), ISZ and amphotericin B (AMB), and the minimal effective concentration (MEC) of caspofungin (CAS) against A. fumigatus BMU10672 was 1 μg/ml, 2 μg/mL, 0.5 μg/mL, 2 μg/mL, 1 μg/mL and 0.125 μg/mL, respectively. The results of E-test and disk diffusion assay were consistent with those of the broth microdilution method (Figs. 1a and b). Together, these results indicate that A. fumigatus BMU10672 is resistant to VRC and ISZ, while being susceptible to ITC, POS, AMB, and CAS. Sequencing of the cyp51A, cyp51B and hmg1 gene of A. fumigatus BMU10672 were all intact. The basal and VRC- or ISZ- induced expression levels of efflux pumps gene cdr1B in A. fumigatus BMU10672 were all higher (> 4-fold) than those in triazole-susceptible A. fumigatus Af293. However, no differences in basal and VRC- or ISZ- induced expression levels of cyp51A gene and cyp51B gene were observed between A. fumigatus BMU10672 and Af293. The efflux pump substrate Nile red accumulation assay showed the A. fumigatus BMU10672 accumulated less Nile red than Af293, confirming that Cdr1B was active at exporting Nile red, while efflux pumps inhibitor FK520 can increase the accumulation of the Nile red in A. fumigatus BMU10672 (Fig. 1c). Inhibition of efflux pumps activity by inhibitor FK520 resulted in a MIC reduction of 4-fold in VRC and ISZ MICs, and 2-fold in ITC and POS, against A. fumigatus BMU10672 (Figs. 1a and b).ConclusionOverexpression of efflux pumps gene cdr1B resulting in VRC- and ISZ- resistance in the clinical isolate of A. fumigatus BMU10672.

S3.4a The repurposing approach identifies pitavastatin (calcium) making fluconazole fungicidal by inhibiting ergosterol synthesis

S3.4 Free oral paper session, September 21, 2022, 4:45 PM - 6:15 PMObjectivesMaking fluconazole (FLC) fungicidal in combination with adjuvants is a promising strategy to avoid the emergence of FLC resistance and eliminate the persistence and recurrence of fungal infections. To address this question, we combined in vitro screening of a library of FDA-approved drugs to identify compounds for making FLC fungicidal.MethodsWe performed a high-throughput screen of an FDA-approved compound library (HY-L022, MCE®), which contains 2372 drugs, to identify potentially novel FLC synergistic lethal adjuvants using broth microdilution and dose-matrix titration assays. The abilities of candidate drugs to turn FLC from fungistatic to fungicidal were further investigated by FLC disk diffusion assays carried out by four tested strains with different FLC tolerance levels (SC5314, SN152, cmp1-aid∆/cmp1-aid∆, and ADH1p-UPC2 strains). We determined the median lethal dose (LD50) of Candidate compounds by the Up-and-Down procedure (UDP) (OECD 425, 2008) via the intraperitoneal route in adult mice and used cyclosporine A and geldanamycin as control drugs to screen FLC synergistic lethal adjuvants with lower toxicity. Finally, we constructed heterozygous deletion mutants for ergosterol synthesis-related genes to identify the mechanism of action of the synergistic lethality of pitavastatin (calcium) (PIT) and FLC (Fig. 1a).ResultsWe found that 200 compounds (≤100 μm) could make FLC (4 μg/ml) fungicidal and further confirmed that 30 compounds turned FLC (4 μg/ml) from fungistatic to fungicidal at a concentration lower than 12.5 μm by broth microdilution assays (Fig. 1b). We further identified that 12/30 compounds (≤3.125 μm) can make FLC fungicidal (≤4 μg/ml) using dose-matrix titration assays. Among these compounds, PIT can make FLC fungicidal at as low as 0.78 μm (Fig. 1c). In the FLC disk diffusion assay, we identified 8 compounds (5 μm) that were superior to or equivalent to the abilities of the control drugs to eliminate the FLC tolerance of four tested strains. It was worth noting that PIT could make FLC fungicidal against all four tested strains (Fig. 1d). The LD50 value of PIT is 103.6 mg/kg and the highest of the tested compounds. Spot assay results showed feeding exogenous 100 μm ergosterol counteracted the antifungal activity of PIT (16 μm) (Fig. 2a), but did not restore the growth defect of Tet-HMG1/hmg1∆ mutant, in which the HMG1 gene expression would be inhibited by tetracycline (Fig. 2b). This paradoxical phenotype suggests that Hmg1 is unlikely to be a target of PIT. We found four heterozygous deletion mutants increased susceptibility to PIT (Fig. 2c) and the growth defect of ERG8/erg8∆ and IDI1/idi1∆ mutants exposed to PIT can be restored by ergosterol (Fig. 2d), suggesting that Erg8 and Idi1 are potential targets of PIT.ConclusionsOur study demonstrates that PIT has a better synergistic lethal effect with FLC by inhibiting ergosterol synthesis and higher safety and suggests that PIT may be repurposed as a promising adjuvant to make FLC fungicidal and enhance the efficacy of FLC in treating invasive fungal infections caused by pathogenic fungi with high FLC tolerance.

Metabolic engineering of Ashbya gossypii for limonene production from xylose

BackgroundLimonene is a cyclic monoterpene that has applications in the food, cosmetic, and pharmaceutical industries. The industrial production of limonene and its derivatives through plant extraction presents important drawbacks such as seasonal and climate issues, feedstock limitations, low efficiency and environmental concerns. Consequently, the implementation of efficient and eco-friendly bioprocesses for the production of limonene and other terpenes constitutes an attractive goal for microbial biotechnology. In this context, novel biocatalysts with the ability to produce limonene from alternative carbon sources will help to meet the industrial demands of limonene.ResultsEngineered strains of the industrial fungus Ashbya gossypii have been developed to produce limonene from xylose. The limonene synthase (LS) from Citrus limon was initially overexpressed together with the native HMG1 gene (coding for HMG-CoA reductase) to establish a limonene-producing platform from a xylose-utilizing A. gossypii strain. In addition, several strategies were designed to increase the production of limonene. Hence, the effect of mutant alleles of ERG20 (erg20F95W and erg20F126W) were evaluated together with a synthetic orthogonal pathway using a heterologous neryl diphosphate synthase. The lethality of the A. gossypii double mutant erg20F95W−F126W highlights the indispensability of farnesyl diphosphate for the synthesis of essential sterols. In addition, the utilization of the orthogonal pathway, bypassing the Erg20 activity through neryl diphosphate, triggered a substantial increase in limonene titer (33.6 mg/L), without critically altering the fitness of the engineered strain. Finally, the overexpression of the native ERG12 gene further enhanced limonene production, which reached 336.4 mg/L after 96 h in flask cultures using xylose as the carbon source.ConclusionsThe microbial production of limonene can be carried out using engineered strains of A. gossypii from xylose-based carbon sources. The utilization of a synthetic orthogonal pathway together with the overexpression of ERG12 is a highly beneficial strategy for the production of limonene in A. gossypii. The strains presented in this work constitute a proof of principle for the production of limonene and other terpenes from agro-industrial wastes such as xylose-rich hydrolysates in A. gossypii.

High-Throughput and Accurate Determination of Transgene Copy Number and Zygosity in Transgenic Maize: From DNA Extraction to Data Analysis.

It is vital to develop high-throughput methods to determine transgene copy numbers initially and zygosity during subsequent breeding. In this study, the target sequence of the previously reported endogenous reference gene hmg was analyzed using 633 maize inbred lines, and two SNPs were observed. These SNPs significantly increased the PCR efficiency, while the newly developed hmg gene assay (hmg-taq-F2/R2) excluding these SNPs reduced the efficiency into normal ranges. The TaqMan amplification efficiency of bar and hmg with newly developed primers was calculated as 0.993 and 1.000, respectively. The inter-assay coefficient of variation (CV) values for the bar and hmg genes varied from 1.18 to 2.94%. The copy numbers of the transgene bar using new TaqMan assays were identical to those using dPCR. Significantly, the precision of one repetition reached 96.7% of that of three repetitions of single-copy plants analyzed by simple random sampling, and the actual accuracy reached 95.8%, confirmed by T1 and T2 progeny. With the high-throughput DNA extraction and automated data analysis procedures developed in this study, nearly 2700 samples could be analyzed within eight hours by two persons. The combined results suggested that the new hmg gene assay developed here could be a universal maize reference gene system, and the new assay has high throughput and high accuracy for large-scale screening of maize varieties around the world.

Azole and echinocandin resistance mechanisms and genotyping of Candida tropicalis in Japan: cross-boundary dissemination and animal–human transmission of C. tropicalis infection

ObjectivesTo assess the prevalence and genetic basis of antifungal resistance mechanisms as well as the genotyping of Candida tropicalis from clinical and non-clinical sources in Japan. MethodsEighty C. tropicalis isolates, including 32 clinical isolates recovered from 29 patients and 48 non-clinical isolates recovered from 24 different sources (animals and the environment) were evaluated. All isolates were tested phenotypically for resistance to a wide range of antifungals and genotypically for resistance mechanisms to azole and echinocandin. Furthermore, all the isolates were genotyped by multilocus sequence typing (MLST). ResultsPhenotypically, 30.2% (16/53) of the isolates were azole-resistant, with high levels of azole resistance among clinical isolates (51.7%; 15/29) and low levels (4.2%; 1/24) among non-clinical isolates. None of the isolates were reported as echinocandin resistant, with 60.4% (32/53) of the isolates intermediate to caspofungin. Azole resistance was basically attributed to high expression levels of drug efflux transporter genes (CDR2 and CDR3), transcription factors (TAC1 and UPC2) and ergosterol biosynthesis pathway HMG gene. No FKS1 hot spot 1 (HS1) or HS2 missense mutations were detected in any of the isolates. MLST analysis revealed 36 different sequence types (STs), with the first identification of 23 new STs. Phylogenetic analysis confirmed the close relationship between the clinical and non-clinical isolates, with identifications of ST232 and ST933 among patients and marine mammals. ConclusionOur results confirmed the emergence of azole resistance in C. tropicalis in Japan. Furthermore, phylogenetic analysis confirmed the transboundary dissemination and cross-transmission of C. tropicalis between humans and animals.

Production of (−)-α-bisabolol in metabolically engineered Saccharomyces cerevisiae

(−)-α-Bisabolol is a natural monocyclic sesquiterpene alcohol present in German chamomile and has been used as an ingredient of functional foods, cosmetics and pharmaceuticals. In this study, metabolic engineering strategies were attempted to produce (−)-α-bisabolol in Saccharomyces cerevisiae. The codon-optimized MrBBS gene coding for (−)-α-bisabolol synthase from Matricaria recutita was expressed in S. cerevisiae for (−)-α-bisabolol production. The resulting strain (DM) produced 9.5 mg/L of (−)-α-bisabolol in 24 h of batch culture. Additionally, the mevalonate pathway was intensified by introducing a truncated HMG1 gene coding for HMG-CoA reductase and ERG10 encoding acetyl-CoA thiolase. The resulting strain (DtEM) produced a 2.9-fold increased concentration of (−)-α-bisabolol than the DM strain. To increase the acetyl-CoA pool, the ACS1 gene coding for acetyl-CoA synthetase was also overexpressed in the DtEM strain. Finally, the DtEMA strain produced 124 mg/L of (−)-α-bisabolol with 2.7 mg/L-h of productivity in a fed-batch fermentation, which were 13 and 6.8 times higher than the DM strain in batch culture, respectively. Conclusively, these metabolically-engineered approaches might pave the way for the sustainable production of other sesquiterpenes in engineered S. cerevisiae.

Hmg1 mutations in Aspergillus fumigatus and their contribution to triazole susceptibility.

The number of triazole-resistant Aspergillus fumigatus is increasing. We confirmed thatmutation in a hydroxymethylglutaryl-CoA reductase (Hmg1) in the fungus contributesto the resistance separately from Cyp51A mutation, and that susceptibility patterns aredifferent based on mutation site.

Taxonomy of the Trichophyton mentagrophytes/T. interdigitale Species Complex Harboring the Highly Virulent, Multiresistant Genotype T. indotineae

A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the Trichophyton mentagrophytes/T. interdigitale complex is ongoing in India. The correct identity of the etiologic agent is a much-debated issue. In order to define species limits, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification. Molecular characteristics show that T. mentagrophytes s. str. and T. interdigitale s. str. can be distinguished with difficulty from each other, but are unambiguously different from the Indian genotype, T. indotineae by sequences of the HMG gene. The entities were confirmed by multilocus analysis using tanglegrams. Phenotypic characters of morphology and physiology are not diagnostic, but statistically significant differences are observed between the molecular siblings. These properties may be drivers of separate evolutionary trends. Trichophyton mentagrophytes represents the ancestral, homothallic cloud of genotypes with a probable geophilic lifestyle, while T. indotineae and T. interdigitale behave as anthropophilic, clonal offshoots. The origin of T. indotineae, which currently causes a significant public health problem, is zoonotic, and its emergence is likely due to widespread misuse of antifungals.

Transition of triazole-resistant Aspergillus fumigatus isolates in a Japanese tertiary hospital and subsequent genetic analysis

ObjectiveTo evaluate the annual variation in the frequency of patient-acquired azole-resistant Aspergillus fumigatus (ARAf), and correlate it to the amount of oral triazole prescribed, in Nagasaki, Japan. MethodsA. fumigatus isolates from respiratory specimens collected in the Nagasaki University Hospital (NUH) between 1996 and 2017 were included in the study. The amount of oral triazole prescribed in NUH since 2001 was obtained from the medical ordering system. Mutations in cyp51A, hmg1, and erg6 genes of ARAf were also analysed. ResultsFrom a total of 240 ARAf strains, 12 (5%), 6 (2.5%), 15 (6.25%), and 3 (1.25%) strains were resistant to itraconazole (ITC), voriconazole (VRC), to either ITC or VRC, and both triazoles, respectively. The amount of prescribed VRC increased annually, and was three times as large as that of ITC in 2017. All eleven patients harbouring ITC-resistant strains had a history of prior ITC treatment, while only one of six patients harbouring VRC-resistant strains had a history of prior VRC treatment. cyp51A mutations were recorded in 10 strains; however, tandem repeat mutations of the promoter region of cyp51A were not observed. Several azole-resistant strains had non-cyp51A mutations. ConclusionsThe frequency of patient-acquired ARAf is not increasing in Nagasaki, Japan. Furthermore, the prevalence of VRC-induced ARAf was rare despite the remarkable increase in the amount of prescribed VRC. Mutations in genes other than cyp51A should also be considered when ARAf strains are obtained from patients treated with azole antifungals.

Hmg1 Gene Mutation Prevalence in Triazole-Resistant Aspergillus fumigatus Clinical Isolates.

Recently, mutations in the 3-hydroxy-3-methylglutaryl-coenzyme-A-reductase-encoding gene (hmg1), a gene involved in ergosterol production, were associated with triazole-resistance in Aspergillus fumigatus. In this study, we determined the prevalence and characteristics of hmg1 mutations in a collection of clinical triazole-resistant A. fumigatus isolates collected during 2001–2019 from two international mycology reference centers: the Belgian National Reference Center for Mycosis and the Center of Expertise in Mycology Radboudumc/CWZ. Clinical isolates with and without cyp51A gene mutations and randomly selected wild-type (WT) controls were included. Isolates were characterized by in vitro susceptibility testing, cyp51A and hmg1 sequencing, and short tandem repeat typing. Available clinical records were analyzed for previous triazole exposure. In 23 isolates (24%) of the 95 triazole-resistant A. fumigatus isolates, hmg1 gene mutations were observed; including 5/23 (22%) isolates without cyp51A gene mutations and 18/72 (25%) with cyp51A mutations. Four previously described hmg1 gene mutations (E105K, G307R/D, G466V, and S541G) and two novel mutations (W273S and L304P) were found; 4/23 (17%) in the sterol-sensing-domain region. No triazole-antifungal exposure was reported in 75% (9/12) of patients harboring an isolate with hmg1 gene mutations. Three of 39 WT isolates (8%) contained a hmg1 gene mutation; E105K (2-isolates) and S541G. Hmg1 gene mutations were predominantly found in A. fumigatus with cyp51A mutations with voriconazole MICs ≥ 8 mg/L.

Abstract 2517: Ectopic expression of miR-142-3p suppresses growth, migration, colony formation and induces apoptosis by down-regulating HMGA1, HMGA2, HMGB1 and HMGB3 in human cervical cancer cells

Abstract High Mobility Group (HMG) proteins are non-histone chromosomal proteins having molecular weight less than 30 kDa. Canonical HMG family of proteins include HMGA (A1 and A2), HMGB (B1, B2, B3, and B4) and HMGN (N1, N2, N3, N4 and N5). Overexpression of HMG proteins contributing to their oncogenic properties has been reported and thus inhibition of their expression is potentially a promising therapeutic strategy in different cancers. Earlier, our laboratory demonstrated that miR-214 downregulates HMGA1 and miR-34a downregulates HMGB1 leading to the suppression of growth, proliferative and invasive properties of human cervical and colorectal cancer cells. Prompted by these results, we tried to find a single miRNA which can target multiple HMG genes. To this end, TargetScan, miRWalk, and miRDB were used to find out miRNAs targeting more than one HMG gene. We found that miR-142-3p has its seed region binding sites in the 3'UTRs of HMGA1, HMGA2, HMGB1, and HMGB3. Survival analysis with OncoLnc server revealed that low miR-142-3p expression found in cervical cancer patients correlates with their poor survival. Strengthened by this classical miRNA-target inverse relationship, we hypothesized that miRNA-142-3p may act as a tumor suppressor by targeting multiple HMG genes in cervical cancer. Doxycycline-responsive miR-142-3p expression constructs were used to generate stable cell lines and functional assays were performed. Through dual-luciferase reporter assays, we demonstrate that all the four HMG genes are direct targets of miR-142-3p in four cervical cancer cell lines (HeLa, SiHa, C33A, and CaSki). We observed the downregulation of the HMG genes (through qRT-PCR) upon miR-142-3p overexpression in the stable cell lines. Also, a significant reduction in cell viability after 72 and 96 hours concurrent with the highest expression levels of miR-142-3p. In colony formation assay, colony-forming potential of the cell lines was found to be severely compromised upon miR-142-3p overexpression. The scratch assay was also performed and a slower rate of migration was observed in miR-142-3p overexpressing cells. Annexin V staining indicated that miR-142-3p induces cell death via apoptosis. These results suggest that miR-142-3p may act as a tumor suppressor in cervical cancer highlighting it as a potential candidate for miRNA replacement therapy. Citation Format: Priyanshu Sharma, Poonam Yadav, Devarajan Karunagaran. Ectopic expression of miR-142-3p suppresses growth, migration, colony formation and induces apoptosis by down-regulating HMGA1, HMGA2, HMGB1 and HMGB3 in human cervical cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2517.

Identification of HMG-box family establishes the significance of SOX6 in the malignant progression of glioblastoma.

Glioblastoma multiforme (GBM) is the most malignant neuroepithelial primary brain tumor and its mean survival time is 15 months after diagnosis. This study undertook to investigate the genome-wide and transcriptome-wide analyses of human high mobility group box (HMG-box) TF (transcript factor) families / HOX, TOX, FOX, HMG and SOX gene families, and their relationships to GBM. According to the TCGA-GBM profile analysis, differentially expressed HOX, FOX, HMG and SOX gene families (62 DEmRNA) were found in this study. We also analyzed DEmRNA (HMG-box related genes) co-expressed eight DElncRNA in GBM, and constructed a ceRNA network analysis as well. We constructed 50 DElncRNA-DEmiRNA-DEmRNA (HMG-box related genes) pairs between GBM and normal tissues. Then, risk genes SOX6 and SOX21 expression were correlated with immune infiltration levels in GBM. SOX6 also had a strong association with MAPT, GSK3B, FYN and DPYSL4, suggesting that they might be functional members in GBM.

Genome-Wide HMG Family Investigation and Its Role in Glycoalkaloid Accumulation in Wild Tuber-Bearing Solanum commersonii.

Steroidal glycoalkaloids (SGAs) are a class of nitrogen-containing glycosides occurring in several plant families and biosynthesized through a specific pathway. HMG-CoA reductase is the first enzyme of this pathway, and its transcription can be regulated by biotic and abiotic stressors and even in a tissue-specific manner. This study aimed to characterize the HMG genes family in a tuber-bearing potato species, Solanum commersonii, using transcriptional and functional approaches. Our results provided evidence that four ScHMGs with different tissue-specificities represent the HMG gene family in S. commersonii and that they originated from ScHMG1 through segmental duplications. Phylogenetic analysis suggests that ScHMG1 is the direct ortholog of AtHMG1, which is associated with SGAs accumulation in plants. Its overexpression in S. commersonii revealed that this gene plays a key role in the accumulation of glycoalkaloids regulating the production of dehydrocommersonine.

Genomic perspective of triazole resistance in clinical and environmental Aspergillus fumigatus isolates without cyp51A mutations

Aspergillus fumigatus is the most common etiologic agent of primarily all clinical manifestations of aspergillosis. A steady increase in the number of azole resistant A. fumigatus (ARAF) isolates from environment and clinical samples leading to therapeutic failures in clinical settings have alarmed the mycologists and clinicians worldwide. Although mutations in azole target cyp51A gene have been implicated in conferring azole resistance in A. fumigatus, recent studies have demonstrated occurrence of azole resistant strains without cyp51A mutations. In this study, next generation sequencing techniques and the expression profiling of transporter genes with single nucleotide polymorphisms (SNPs) in clinical and environmental ARAF isolates with (G54E) and without known cyp51A mutations was undertaken to understand the genetic background and role of transporters in azole resistance. The raw reads of four ARAF strains when mapped to Af293 reference genome (>100X depth) covered at least 93.1% of the reference genome. Among all four strains, a total of 212,711 SNPs was identified with 37,829 were common in at least two isolates. The expression analysis suggested the overexpression of MFS transporter, namely, mfsC in all ARAF isolates. None of the resistant strain showed significant upregulation of cyp51A and cyp51B gene. On the other hand, abcD was upregulated (5-fold) in the isolates with cyp 51A mutation (G54E). The whole genome sequence analysis showed the presence of two previously described amino acid substitutions S269F and F390Y in HMG1 gene in a clinical panazole resistant strain without cyp51A mutations. These mutations have been previously associated with azole resistance in A. fumigatus strains without cyp51A mutations. Further, several punctual mutations and a large-segment deletion among different strains were observed suggesting the involvement of resistance mechanisms other than cyp51A.

Enhancing carotenoid production in Rhodotorula mucilaginosa KC8 by combining mutation and metabolic engineering

Rhodotorula mucilaginosa has been considered as a potential industrial yeast due to its unicellular and fast-growing characteristics, and its ability to produce carotenoids, including torularhodin. However, its low total carotenoid production limits its commercial application. In this study, mutation breeding and metabolic engineering were employed to enhance carotenoid production in the R. mucilaginosa strain KC8. After chemical–physical mutagenesis, R. mucilaginosa K4 with a 67% greater concentration of carotenoids (14.47 ± 0.06 mg L−1) than R. mucilaginosa KC8 (8.67 ± 0.07 mg L−1) was obtained. To further enhance carotenoid production, gene HMG1 encoding the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was introduced from another yeast, Saccharomyces cerevisiae, and overexpressed in R. mucilaginosa K4. The carotenoid production of HMG1-gene-overexpression transformant G1 reached 16.98 mg L−1. To relieve the feedback inhibition of ergosterol, and to down-regulate ergosterol synthesis, ketoconazole, an ergosterol synthesis inhibitor, was added at a concentration of 28 mg L−1. The carotenoid production of the transformant G1 reached 19.14 ± 0.09 mg L−1, which was 121% higher than in R. mucilaginosa KC8. This suggests that a combination of chemical–physical mutagenesis, overexpression of the HMG1 gene, and adding ketoconazole is an effective strategy to improve carotenoid production.

Morphological features of the transgenic tobacco plant shoot expressing the 3-hydroxy-3-methylglutagyl-CoA reductase (HMG1) gene in the direct and reverse orientations towards the promoter

3-Hydroxy-3-methylglutaryl-CoA reductase (HMG1) catalyzes the formation of mevalonic acid, the key intermediate of the cytosolic isoprenoid synthesis pathway. The parameters of stem and leaf growth were studied in the transgenic tobacco plants that express the HMG1 gene in both sense and antisense orientations towards the constitutive promoter. The transgenic plant height did not significantly differ from that of the control plants, though the plants carrying the sense copy of the HMG1 gene were considerably taller than plants that carried the antisense gene copy. Plants carrying an extra copy of the HMG1 gene were also characterized by increased leaf area. The number of mesophyll cells calculated per square unit of transgenic plants leaves was smaller than in the control plant leaves, though their volume was not considerably changed in any of the variants, suggesting changes in the cell packing density in leaves.