Chemo-Enzymatic Strategy for the Efficient Synthesis of Steroidal Drugs with 10α-Methyl Group and a Side Chain at C17-Position from Biorenewable Phytosterols.

Steroidal pharmaceuticals with a 10α-methyl group or without the methyl group at C10-position are important medicines, but their synthesis is quite challenging, due to that the natural steroidal starting materials usually have a 10ß-methyl group which is difficult to be inverted to 10α-methyl group. In this study, 3-((1R,3aS,4S,7aR)-1-((S)-1-hydroxypropan-2-yl)-7a-methyl-5-oxooctahydro-1H-inden-4-yl) propanoic acid (HIP-IPA, 2e) was demonstrated as a valuable intermediate for the synthesis of this kind of active pharmaceutical ingredients (APIs) with a side chain at C17-position. Knockout of a ß-hydroxyacyl-CoA dehydrogenase gene and introduction of a sterol aldolase gene into the genetically modified strains of Mycobacterium fortuitum (ATCC 6841) resulted in strains N13Δhsd4AΩthl and N33Δhsd4AΩthl, respectively. Both strains transformed phytosterols into 2e. Compound 2e was produced in 62% isolated yield (25 g) using strain N13Δhsd4AΩthl, and further converted to (3S,3aS,9aS,9bS)-3-acetyl-3a,6-dimethyl-1,2,3,3a,4,5,8,9,9a,9b-decahydro-7H-cyclopenta[a]naphthalen-7-one, which is the key intermediate for the synthesis of dydrogesterone. This study not only overcomes a challenging synthetic problem by enabling an efficient synthesis of dydrogesterone-like steroidal APIs from phytosterols, the well-recognized cheap and readily available biobased raw materials, but also provides insights for redesigning the metabolic pathway of phytosterols to produce other new compounds of relevance to the steroidal pharmaceutical industry.

Development and validation of a prediction model for early screening of people at high risk for colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a serious threat worldwide. Although early screening is suggested to be the most effective method to prevent and control CRC, the current situation of early screening for CRC is still not optimistic. In China, the incidence of CRC in the Yangtze River Delta region is increasing dramatically, but few studies have been conducted. Therefore, it is necessary to develop a simple and efficient early screening model for CRC. AIM: To develop and validate an early-screening nomogram model to identify individuals at high risk of CRC. METHODS: Data of 64448 participants obtained from Ningbo Hospital, China between 2014 and 2017 were retrospectively analyzed. The cohort comprised 64448 individuals, of which, 530 were excluded due to missing or incorrect data. Of 63918, 7607 (11.9%) individuals were considered to be high risk for CRC, and 56311 (88.1%) were not. The participants were randomly allocated to a training set (44743) or validation set (19175). The discriminatory ability, predictive accuracy, and clinical utility of the model were evaluated by constructing and analyzing receiver operating characteristic (ROC) curves and calibration curves and by decision curve analysis. Finally, the model was validated internally using a bootstrap resampling technique. RESULTS: Seven variables, including demographic, lifestyle, and family history information, were examined. Multifactorial logistic regression analysis revealed that age [odds ratio (OR): 1.03, 95% confidence interval (CI): 1.02-1.03, P < 0.001], body mass index (BMI) (OR: 1.07, 95%CI: 1.06-1.08, P < 0.001), waist circumference (WC) (OR: 1.03, 95%CI: 1.02-1.03 P < 0.001), lifestyle (OR: 0.45, 95%CI: 0.42-0.48, P < 0.001), and family history (OR: 4.28, 95%CI: 4.04-4.54, P < 0.001) were the most significant predictors of high-risk CRC. Healthy lifestyle was a protective factor, whereas family history was the most significant risk factor. The area under the curve was 0.734 (95%CI: 0.723-0.745) for the final validation set ROC curve and 0.735 (95%CI: 0.728-0.742) for the training set ROC curve. The calibration curve demonstrated a high correlation between the CRC high-risk population predicted by the nomogram model and the actual CRC high-risk population. CONCLUSION: The early-screening nomogram model for CRC prediction in high-risk populations developed in this study based on age, BMI, WC, lifestyle, and family history exhibited high accuracy.

Fruquintinib for refractory colorectal cancer in a pre-treated 82-year-old patient achieved a progression-free survival of 25 months: a case report.

Background: Chemotherapy was recommended as the 1st or 2nd line standard of care for patients with refractory or metastatic colorectal cancer (mCRC). Extra cautions are needed for elderly patients, because cytotoxic regimens may induce unexpected adverse effects due to their impaired physical condition and tolerability. Currently, there is no evidence for the treatment in elderly patients. This case reports a new ideas to the treatment of elderly mCRC patients. Case Description: An 82-year-old man was diagnosed with descending colon cancer and underwent radical operation revealed stage IIIB cancer (pT4aN1cM0) in June 2016, followed by adjuvant chemotherapy (6 cycles of XELOX). The disease relapsed in June 2018, and the patient was prescribed Tegafur for 6 months. In December 2018, he was admitted to hospital due to intestinal obstruction with performance status (PS) score of 3 and nutrition score (NRS2002) of 5. According to a multidisciplinary team (MDT) meeting: considering that the adverse effects of front-line treatment are dominated by myelosuppression, the general condition of the patient is currently poor. The patient received fruquintinib as the second-line treatment which was interrupted for one month due to grade 3 hypertension and proteinuria. The restarted dose was reduced from 5 to 3 mg/day and continued until the last follow-up. The disease did not progress during 25-months of Fruquintinib treatment. Unfortunately, the patient was bedridden for a long time after an accidental fall resulting in a pulmonary infection and finally died of respiratory failure in January 2021. Conclusions: CRC patients with advanced age and poor general condition require MDT meetings and individualized treatment. Despite of an advanced age, poor physical condition, and intense tumor burden, Fruquintinib as the second-line treatment achieved satisfactory disease control in this case. Adverse events could be relieved by dose reduction. Thus, fruquintinib could be a treatment option in refractory elderly CRC patients.

Asymmetric Synthesis of Fused-Ring Tetrahydroisoquinolines and Tetrahydro-ß-carbolines from 2-Arylethylamines via a Chemoenzymatic Approach.

While chiral fused-ring tetrahydroisoquinoline (THIQ) and tetrahydro-ß-carboline (THßC) scaffolds have attracted considerable interest due to their wide spectrum of biological activities, the synthesis of optically pure chiral fused-ring THIQs and THßCs remains a challenging task. Herein, a group of active imine reductases were identified to convert the imine precursors into the corresponding enantiocomplementary fused-ring THIQs and THßCs with high enantioselectivity and conversion, establishing an efficient and green chemoenzymatic approach to fused-ring alkaloids from 2-arylethylamines.

Prognostic signatures and potential pathogenesis of eRNAs-related genes in colon adenocarcinoma.

Enhancer RNAs (eRNAs) are a subclass of long noncoding RNAs (lncRNAs) that have a wide effect in human tumors. However, the systematic analysis of potential functions of eRNAs-related genes (eRGs) in colon cancer (CC) remains unexplored. In this study, a total of 8231 eRGs including 6236 protein-coding genes and 1995 lncRNAs were identified in CC based on the multiple resources. These eRGs showed higher expression level and stability compared to other genes. What's more, the functions of these eRGs were closely related to cancer. Then a prognostic prediction model with 12 eRGs signatures were obtained for colon adenocarcinoma (COAD) patients. ROC curves showed the AUCs were 0.81, 0.77, and 0.78 for 1-, 3-, and 5-year survival prediction, respectively. And the prognostic model also manifested good performance in the validation datasets. Besides, the expression levels of two prognostic signatures, TMEM220 and LRRN2, were verified to be significantly lower in CC tissues than in adjacent noncancerous tissues (p < .05). Finally, the distinct molecular features were characterized between the high- and low-risk group through multiomics analysis including DNA mutation and methylation. Our results show eRGs signatures based prognostic model has high accuracy and may provide innovative biomarkers in COAD.

Regulatory Network Analysis of Mutated Genes Based on Multi-Omics Data Reveals the Exclusive Features in Tumor Immune Microenvironment Between Left-Sided and Right-Sided Colon Cancer.

Left-sided colon cancer (LCC) and right-sided colon cancer (RCC) have distinct characteristics in tumor immune microenvironment (TIME). Although existing studies have shown a strong association between gene mutations and TIME, whether the regulatory mechanisms between gene mutations and TIME are different between RCC and LCC is still unclear. In this study, we showed the fractions of CD8+ T cells were higher while those of regulatory T cells were lower in RCC. Besides, a stronger association between gene mutations and TIME was observed in RCC. Specifically, using multi-omics data, we demonstrated the mutations of most top mutated genes (TMGs) including BRAF, PCLO, MUC16, LRP2, ANK3, KMT2D, RYR2 made great contributions to elevated fraction of immune cells by up-regulating immune-related genes directly or indirectly through miRNA and DNA methylation, whereas the effects of APC, TP53 and KRAS mutations on TIME were reversed in RCC. Remarkably, we found the expression levels of several immune checkpoint molecules such as PD-1 and LAG3 were correlated with corresponding DNA methylation levels, which were associated with the mutations of TMGs in RCC. In contrast, the associations between gene mutations and TIME were less significant in LCC. Besides, survival analyses showed APC mutation had adverse impact on immunotherapy while patients with BRAF mutation were more suitable for immunotherapy in colon cancer. We hope that our results will provide a deeper insight into the sophisticated mechanism underlying the regulation between mutations and TIME, and thus boost the discovery of differential immunotherapeutic strategies for RCC and LCC.

Crystal Structures and Catalytic Mechanism of l-erythro-3,5-Diaminohexanoate Dehydrogenase and Rational Engineering for Asymmetric Synthesis of ß-Amino Acids.

Amino acid dehydrogenases (AADHs) have shown considerable potential as biocatalysts in the asymmetric synthesis of chiral amino acids. However, compared to the widely studied α-AADHs, limited knowledge is available about ß-AADHs that enable the synthesis of ß-amino acids. Herein, we report the crystal structures of a l-erythro-3,5-diaminohexanoate dehydrogenase and its variants, the only known member of ß-AADH family. Crystal structure analysis, site-directed mutagenesis studies and quantum chemical calculations revealed the differences in the substrate binding and catalytic mechanism from α-AADHs. A number of rationally engineered variants were then obtained with improved activity (by 110-800 times) toward various aliphatic ß-amino acids without an enantioselectivity trade-off. Two ß-amino acids were prepared by using the outstanding variants with excellent enantioselectivity (>99 % ee) and high isolated yields (86-87 %). These results provide important insights into the molecular mechanism of 3,5-DAHDH, and establish a solid foundation for further design of ß-AADHs for the asymmetric synthesis of ß-amino acids.

Telomere in colorectal cancer associated with distant metastases and predicted a poor prognosis.

BACKGROUND: Telomere is essential for chromosomal stability and its length has been proven to be related to prognosis in many malignant tumors. This study aims to investigate the relevance of telomere length with clinical and pathologic features and its prognostic value in colorectal cancer (CRC). METHODS: Telomere status of CRC and adenoma cells were measured by telomere-specific quantitative fluorescent in situ hybridization (Q-FISH). The relative telomere length (RTL) was calculated as the mean telomere fluorescent intensity units (TFUs) in carcinoma cell divided by the TFU in cancer-associated fibroblast cell (CAF). RESULTS: One hundred CRC patients, who were received surgery treatment during 2013 to 2014 and fifty-seven patients who underwent the examination of colonoscope and were confirmed as adenoma were enrolled. TFUs of carcinoma cell and CAF were statistically significantly lower than in adjacent mucosa cell (P=0.0079). Although there was no difference between the three kinds of adenoma cells (P=0.5457), TFU in adenoma cells was significantly lower than in CAF (P<0.0001) and independent with age. TFU and the RTL were statistically significantly lower in adenoma cells than in carcinoma (all P<0.0001). TFU of carcinoma cell in distant metastases patients were significantly lower than that without distant metastases patients (P=0.002). When cut by the median value of TFU of carcinoma cell and RTL, patients with a lower TFU or RTL had statistically significantly poorer overall survival (OS) (P=0.0027, HR: 4.6, 95% CI: 1.9-11.0; P=0.0163, HR: 2.95, 95% CI: 1.22-7.12) and disease-free survival (DFS) (P=0.0057, HR: 3.14, 95% CI: 1.40-7.06; P=0.0271, HR: 2.49, 95% CI: 1.11-5.59, respectively) than those patients with higher TFU or RTL. On multivariate analysis, the TFU of carcinoma cell was proved to be an independent prognostic value both for OS and DFS (P=0.0005, HR: 4.975, 95% CI: 1.616-15.385; P=0.007, HR: 3.57, 95% CI: 1.410-9.010). CONCLUSIONS: The length of telomere in carcinoma and adenoma cells were consistently shorter and the telomere changes were early carcinogenesis event, even the epithelial cells were morphologically not malignant. The length of telomere was associated with tumor metastases and prognosis, suggesting telomere probably was an important cue of the biological behavior of CRC.

Inverting the Enantiopreference of Nitrilase-Catalyzed Desymmetric Hydrolysis of Prochiral Dinitriles by Reshaping the Binding Pocket with a Mirror-Image Strategy.

A mirror-image strategy, that is, symmetry analysis of the substrate-binding pocket, was applied to identify two key amino acid residues W170 and V198 that possibly modulate the enantiopreference of a nitrilase from Synechocystis sp. PCC6803 towards 3-isobutyl glutaronitrile (1 a). Exchange of these two residues resulted in the enantiopreference inversion (S, 90 % ee to R, 47 % ee). By further reshaping the substrate-binding pocket via routine site-saturation and combinatorial mutagenesis, variant E8 with higher activity and stereoselectivity (99 % ee, R) was obtained. The mutant enzyme was applied in the preparation of optically pure (R)-3-isobutyl-4-cyanobutanoic acid ((R)-2 a) and showed similar stereopreference inversion towards a series of 3-substituted glutaronitriles. This study may offer a general strategy to switch the stereopreference of other nitrilases and other enzymes toward the desymmetric reactions of prochiral substrates with two identical reactive functional groups.

Highly Diastereoselective Synthesis of 2,2-Disubstituted Cyclopentane-1,3-diols via Stepwise Ketone Reduction Enabling Concise Chirality Construction.

A series of 2,2-disubstituted trans,cis-cyclopentane-1,3-diols were synthesized in >99% dr through enzymatic reduction of enantiopure 2,2-disubstituted 3-hydroxycyclopentane-1-ones, which were prepared by highly stereoselective enzymatic reduction of the corresponding cyclodiketones. For 2-benzyl-2-methyl-3-oxocyclopentyl acetate, acetylation of the hydroxyl group significantly affected the reduction stereoselectivity, giving trans,cis-, trans,trans-, and cis,cis-2-benzyl-2-methyl-cyclopentane-1,3-diols in stereomerically pure form. This efficient and environmentally friendly method provides a practical approach to the synthesis of these chiral building blocks in single stereoisomeric form, demonstrating the power of biocatalysis in the concise chirality construction of complex chiral molecules.

Comparison of Gut Microbiome in Human Colorectal Cancer in Paired Tumor and Adjacent Normal Tissues.

BACKGROUND: To understand the biological effect of gut microbiome on the progression of colorectal cancer (CRC), we sequenced the V3-V4 region of the 16S rRNA gene to illustrate the overall structure of microbiota in the CRC patients. METHODS: In this study, a total of 66 CRC patients were dichotomized into different groups based on the following characteristics: paired tumor and adjacent normal tissues, distal and proximal CRC segments, MMR (-) and MMR (+), different TNM staging and clinic tumor staging. RESULTS: By sequencing and comparing the microbial assemblages, our results indicated that 7 microbe genus (Fusobacterium, Faecalibacterium, Akkermansia, Ruminococcus2, Parabacteroides, Streptococcus, and f_Ruminococcaceae) were significantly different between tumor and adjacent normal tissues; and 5 microbe genus (Bacteroides, Fusobacterium, Faecalibacterium, Parabacteroides, and Ruminococcus2) were significantly different between distal and proximal CRC segments; only 2 microbe genus (f_Enterobacteriaceae and Granulicatella) were significantly different between MMR (-) and MMR (+); but there was no significant microbial difference were detected neither in the TNM staging nor in the clinic tumor staging. CONCLUSION: All these findings implied a better understanding of the alteration in the gut microbiome, which may offer new insight into diagnosing and therapying for CRC patients.

Ultrasound-assisted synthesis of pyrroles catalyzed by zirconium chloride under solvent-free conditions.

A straightforward synthesis of substituted pyrroles using zirconium chloride-catalyzed modified Paal-Knorr method has been accomplished under ultrasound irradiation. Compared to known methods, this new method provides as easy access to various substituted pyrroles in good to excellent yields with short reaction times.