Co-overexpression of lmbW and metK led to increased lincomycin A production and decreased byproduct lincomycin B content in an industrial strain of Streptomyces lincolnensis.

AIMS: To improve lincomycin A production and decrease the content of byproduct lincomycin B in an industrial lincomycin-producing strain. METHODS AND RESULTS: The in silico analysis indicated that LmbW could be involved in propylproline biosynthesis of lincomyin A. In this study, we constructed an lmbW deletion mutant and found that the mutant lost the ability to produce lincomycin A, but increased the accumulation of lincomycin B. The loss of lincomycin A production can be restored by complementing the mutant with the expression of lmbW gene. When lmbW and metK (encoding S-adenosylmethionine synthetase) was co-overexpressed, lincomycin A titre was 1744·6 mg l(-1) , a 35·83% improvement over the original strain. Meanwhile, the content of lincomycin B was reduced to 4·41%, a remarkable decrease of 34·76%, compared to that of the original strain. CONCLUSIONS: lmbW encodes a C-methyltransferase involved in the biosynthesis of lincomycin A but not lincomycin B. Co-overexpression of lmbW and metK improved lincomycin A production and decreased the content of lincomycin B. SIGNIFICANCE AND IMPACT OF THE STUDY: The engineered Streptomyces lincolnensis strain shows promising application in the fermentation production of lincomycin A, which may help cut production costs and simplify downstream separation processes.

Correlation of increased MALAT1 expression with pathological features and prognosis in cancer patients: a meta-analysis.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a potential cancer biomarker, yet the mechanism by which it influences the development of cancer remains unknown. In this study, we aimed to correlate MALAT1 expression with pathological features and prognosis in cancer patients. Several databases were searched using combinations of keywords relating to MALAT1 and cancer. After selection of relevant cohort studies according to strict criteria, a meta-analysis was conducted. Twelve studies were analyzed, involving 958 cancer patients. Elevated MALAT1 expression was associated with poor prognosis and larger tumors [prognosis: hazard ratio = 3.11, 95% confidence interval (CI) = 1.98-4.23, P = 0.000; tumor size: odds ratio (OR) = 0.40, 95%CI = 0.21-0.74, P = 0.003]. However, no connection with histological grade, T-stage, lymph node (LN) metastasis, or distant metastasis was established (all P > 0.05). A correlation between increased expression and poor prognosis was observed in the large and small sample-size subgroups (all P< 0.05), as was a relationship with large tumor size (OR = 0.30, 95%CI = 0.13-0.71, P = 0.006). Expression was correlated with T-stage and distant metastasis in the small sample-size subgroup (all P < 0.05), but no association was detected regarding histological grade, LN metastasis in either subgroup (all P > 0.05). Our findings demonstrate that elevated MALAT1 expression correlates with large tumor size, advanced tumor stage, and poor prognosis, and might therefore be utilized to evaluate clinical pathological features and prognostic out come for cancer patients.

Molecular cloning and characterization of cotton cDNAs expressed in developing fiber cells.

Using the FDD-PCR technique, ten new fiber-specific cDNAs were isolated from developing cotton fiber cells and showed high amino acid identity to previously recorded cDNAs. Five cDNAs encoding bisphosphate nucleotidase, alpha-tubulin, beta-galactosidase, annexin, and reversibly glycosylated polypeptide were identified while the functions of five other cDNAs were undetermined. Dot blot analysis showed that all transcripts of the 10 cDNAs accumulated preferentially in fiber cells and the majority were expressed in the early phase of cotton fiber development, except for F14 which accumulated at a high level during the late phase of developing fiber cells, indicating that all of the genes were involved in the process of fiber development.