SOX2 downregulation of PML increases HCMV gene expression and growth of glioma cells.

The presence of human cytomegalovirus (HCMV) in glioblastoma (GBM) and improved outcomes of GBM patients receiving therapies targeting the virus have implicated HCMV in GBM progression. However, a unifying mechanism that accounts for the contribution of HCMV to the malignant phenotype of GBM remains incompletely defined. Here we have identified SOX2, a marker of glioma stem cells (GSCs), as a key determinant of HCMV gene expression in gliomas. Our studies demonstrated that SOX2 downregulated promyelocytic leukemia (PML) and Sp100 and consequently facilitated viral gene expression by decreasing the amount of PML nuclear bodies in HCMV-infected glioma cells. Conversely, the expression of PML antagonized the effects of SOX2 on HCMV gene expression. Furthermore, this regulation of SOX2 on HCMV infection was demonstrated in a neurosphere assay of GSCs and in a murine xenograft model utilizing xenografts from patient-derived glioma tissue. In both cases, SOX2 overexpression facilitated the growth of neurospheres and xenografts implanted in immunodeficient mice. Lastly, the expression of SOX2 and HCMV immediate early 1 (IE1) protein could be correlated in tissues from glioma patients, and interestingly, elevated levels of SOX2 and IE1 were predictive of a worse clinical outcome. These studies argue that HCMV gene expression in gliomas is regulated by SOX2 through its regulation of PML expression and that targeting molecules in this SOX2-PML pathway could identify therapies for glioma treatment.

Molecular landscape of pediatric type IDH wildtype, H3 wildtype hemispheric glioblastomas.

The WHO (2021) Classification classified a group of pediatric-type high-grade gliomas as IDH wildtype, H3 wildtype but as of currently, they are characterized only by negative molecular features of IDH and H3. We recruited 35 cases of pediatric IDH wildtype and H3 wildtype hemispheric glioblastomas. We evaluated them with genome-wide methylation profiling, targeted sequencing, RNAseq, TERT promoter sequencing, and FISH. The median survival of the cohort was 27.6 months. With Capper et al.'s36 methylation groups as a map, the cases were found to be epigenetically heterogeneous and were clustered in proximity or overlay of methylation groups PXA-like (n = 8), LGG-like (n = 10), GBM_MYCN (n = 9), GBM_midline (n = 5), and GBM_RTKIII (n = 3). Histology of the tumors in these groups was not different from regular glioblastomas. Methylation groups were not associated with OS. We were unable to identify groups specifically characterized by EGFR or PDGFRA amplification as proposed by other authors. EGFR, PDGFRA, and MYCN amplifications were not correlated with OS. 4/9 cases of the GBM_MYCN cluster did not show MYCN amplification; the group was also enriched for EGFR amplification (4/9 cases) and the two biomarkers overlapped in two cases. Overall, PDGFRA amplification was found in only four cases and they were not restricted to any groups. Cases in proximity to GBM_midline were all hemispheric and showed loss of H3K27me3 staining. Fusion genes ALK/NTRK/ROS1/MET characteristic of infantile glioblastomas were not identified in 17 cases successfully sequenced. BRAF V600E was only found in the PXA group but CDKN2A deletion could be found in other methylation groups. PXA-like cases did not show PXA histological features similar to findings by other authors. No case showed TERT promoter mutation. Mutations of mismatch repair (MMR) genes were poor prognosticators in single (p ≤ 0.001) but not in multivariate analyses (p = 0.229). MGMT had no survival significance in this cohort. Of the other common biomarkers, only TP53 and ATRX mutations were significant poor prognosticators and only TP53 mutation was significant after multivariate analyses (p = 0.024). We conclude that IDH wildtype, H3 wildtype pediatric hemispheric glioblastomas are molecularly heterogeneous and in routine practice, TP53, ATRX, and MMR status could profitably be screened for risk stratification in laboratories without ready access to methylation profiling.

Integrative genomic analyses identify WDR12 as a novel oncogene involved in glioblastoma.

Glioblastoma (GBM) is the most malignant primary brain tumor in adults. Due to its invasive nature, it cannot be thoroughly eliminated. WD repeat domain 12 (WDR12) processes the 32S precursor rRNA but cannot affect the synthesis of the 45S/47S primary transcript. In this study, we found that WDR12 is highly expressed in GBM according to the analysis results of mRNA expression by The Cancer Genome Atlas database. The high expression level of WDR12 is dramatically related to shorter overall survival and reduced disease-free survival. Next, we knocked down WDR12 and found that knockdown of WDR12 promoted the apoptosis and inhibited the proliferation by cell biology experiments. Differential expression genes in gene-chip revealed that WDR12 knockdown mainly inhibited cell cycle. Finally, we also found that WDR12 is associated with PLK1 and EZH2 in cell proliferation of GBM. Resumptively, this report showed a possible evidence that WDR12 drove malignant behavior of GBM, whose expression may present a neoteric independent prognostic biomarker in GBM.

Self-Assembly Behavior of Diacetylenic Acid Molecules upon Vapor Deposition: Odd-Even Effect on the Film Morphology.

A series of linear carboxylic acids containing diacetylenic units at different positions along the chain (C12 H25 (C≡C)2 (CH2 )n COOH, n=7-11) were vacuum-deposited on clean silica substrates. The morphologies of the initial films after UV irradiation were studied. A clear odd-even effect on the morphology of the initial film was observed in that, depending on the spacer length between the diacetylenic unit and carboxyl head group, rings or dendrites of acid dimer layers were obtained. A molecular dynamic simulation of the aggregation process suggests that two competing intermolecular interactions and thus aggregation directions are involved and modulated by the odd or even carbon chain length. Further modulation of the interaction by substitution of a phenyl group at the terminus of the chain or by changing the carboxyl head group to an amidobenzoic acid head group led to a similar odd-even effect but with different dimensions or trends, which can be rationalized similarly. These results give the opportunity to create aligned conjugated polymer chains of different dimensions through self-assembly for applications in molecular/organic electronics.

Folding Sheets with Ion Beams.

Focused ion beams (FIBs) are versatile tools with cross-disciplinary applications from the physical and life sciences to archeology. Nevertheless, the nanoscale patterning precision of FIBs is often accompanied by defect formation and sample deformation. In this study, the fundamental mechanisms governing the large-scale plastic deformation of nanostructures undergoing FIB processes are revealed by a series of molecular dynamic simulations. A surprisingly simple linear correlation between atomic volume removed from the film bulk and film deflection angle, regardless of incident ion energy and current, is revealed, demonstrating that the mass transport to the surface of material caused by energetic ion bombardment is the primary cause leading to nanostructure deformation. Hence, by controlling mass transport by manipulation of the incident ion energy and flux, it is possible to control the plastic deformation of nanostructures, thereby fabricating nanostructures with complex three-dimensional geometries.

CPEB4 interacts with Vimentin and involves in progressive features and poor prognosis of patients with astrocytic tumors.

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a regulator of gene transcription and has been reported to be associated with biological malignancy in cancers. However, it is unclear whether CPEB4 has any clinical significance in patients with astrocytic tumors, and mechanisms that CPEB4 contribute to progression of astrocytic tumors remain largely unknown. Here, correlation between CPEB4 expression and prognosis of patients with astrocytic tumors were explored by using qPCR, WB and IHC, and X-tile, SPSS software. Cell lines U251 MG and A172 were used to study CPEB4's function and mechanisms. Co-immunoprecipitation, mass spectrometry, immunofluorescent assay, and western blot were performed to observe the interaction between CPEB4 and Vimentin. CPEB4 mRNA and protein levels were markedly elevated in 12/12 astrocytic tumors in comparison to paratumor. High expression of CPEB4 was significantly correlated with clinical progressive futures and work as an independent adverse prognostic factor for overall survival of patients with astrocytic tumors (relative risk 4.5, 95 % CI 2.1-11.2, p = 0.001). Moreover, knockdown of CPEB4 in astrocytic tumor cells inhibited their proliferation ability , clonogenicity, and invasiveness. Five candidate proteins, GRP78, Mortalin, Keratin, Vimentin, and ß-actin, were identified, and the interaction between CPEB4 and Vimentin was finally confirmed. Downregulation of CPEB4 could reduce the protein expression of Vimentin. Our studies first validated that CPEB4 interacts with Vimentin and indicated that high CPEB4 expression in astrocytic tumors correlates closely with a clinically aggressive future, and that CPEB4 might represent a valuable prognostic marker for patients with astrocytic tumors.

Surgical techniques in radiation induced temporal lobe necrosis in nasopharyngeal carcinoma patients.

BACKGROUND: Radiation induced brain injury ranges from acute reversible edema to late, irreversible radiation necrosis. Radiation induced temporal lobe necrosis is associated with permanent neurological deficits and occasionally progresses to death. OBJECTIVE: We present our experience with surgery on radiation induced temporal lobe necrosis (RTLN) in nasopharyngeal carcinoma (NPC) patients with special consideration of clinical presentation, surgical technique, and outcomes. METHOD: This retrospective study includes 12 patients with RTLN treated by the senior author between January 2010 and December 2014. Patients initially sought medical treatment due to headache; other symptoms were hearing loss, visual deterioration, seizure, hemiparesis, vertigo, memory loss and agnosia. A temporal approach through a linear incision was performed for all cases. RTLN was found in one side in 7 patients, and bilaterally in 5. 4 patients underwent resection of necrotic tissue bilaterally and 8 patients on one side. RESULTS: No death occurred in this series of cases. There were no post-operative complications, except 1 patient who developed aseptic meningitis. All 12 patients were free from headache. No seizure occurred in patients with preoperative epilepsy. Other symptoms such as hemiparesis and vertigo improved in all patients. Memory loss, agnosia and hearing loss did not change post-operatively in all cases. The follow-up MR images demonstrated no recurrence of necrotic lesions in all 12 patients. CONCLUSION: Neurosurgical intervention through a temporal approach with linear incision is warranted in patients with radiation induced temporal lobe necrosis with significant symptoms and signs of increased intracranial pressure, minimum space occupying effect on imaging, or neurological deterioration despite conservative management.

HMME-based PDT restores expression and function of transporter associated with antigen processing 1 (TAP1) and surface presentation of MHC class I antigen in human glioma.

Numerous studies have established that photodynamic therapy (PDT) can trigger tumor-specific immunity and cancer cell immunogenicity, both of which play a critical role in the long-term control of oncogenesis; however, the underlying mechanisms are largely unexplained. Deficiency of the transporter associated with antigen processing 1 (TAP1) has been observed in a variety of tumors, and the question has been raised whether the restoration of TAP1 could facilitate the activation of antitumor immunity. To elucidate the mechanisms underlying PDT-induced immunopotentiation, we examined the hypothesis that upregulating TAP1 via PDT may contribute to enhancement of antitumor immunity and cancer cell immunogenicity. In this study, we investigated the effects of PDT on the expression and function of TAP1 in glioma cells. We found that HMME-based PDT restored TAP1 expression in a rapid and transient manner. Furthermore, the newly synthesized TAP1 protein was capable of potentiating the activity of transporting antigen peptides. As a result, restoration of the expression and function of TAP1 translated into augmenting the presentation of surface MHC class I molecules. Overall, our data indicate that PDT enables glioma cells to recover both the expression of functional TAP1 and the presentation of surface MHC class I antigens, which are processes that may enhance antitumor immunity after PDT. These findings may have implications for PDT and provide new insights into the mechanisms underlying PDT-induced immunopotentiation.

Nogo­66 promotes ß­amyloid protein secretion via NgR/ROCK­dependent BACE1 activation.

The generation of ß­amyloid protein (Aß) is considered a key step in the pathogenesis of Alzheimer's disease (AD) and the regulation of its production is an important therapeutic strategy. It was hypothesized in the present study that Nogo­A may be involved in AD and may regulate the generation of Aß. Nogo­A is known to act as a major inhibitor of neuron regeneration in the adult central nervous system. A recent study indicated that Nogo­A is associated with AD; however, the underlying effect and molecular mechanisms remain largely elusive. In the present study, the potential effects of Nogo­A on AD were investigated. ELISA was used to detect the levels of Aß, enzymatic activity detection kits were used to determine the activity of secretase enzymes in amyloid precursor protein (APP) metabolism, and western blot analysis was used to detect the expression levels of proteins associated with the APP processing and Nogo­A/Nogo­66 receptor (NgR) signaling pathways. The results revealed that Nogo­66, the major inhibitory region of Nogo­A, promoted neuronal Aß secretion by increasing the activity of ß­secretase 1 via the NgR/Rho­associated coiled­coil containing kinases pathway in a dose­dependent manner. The present data suggested that Nogo­A may facilitate the onset and development of AD by promoting Aß secretion, providing information on a potential novel target for AD therapy.

Mismatch repair proteins PMS2 and MLH1 can further refine molecular stratification of IDH-mutant lower grade astrocytomas.

The diagnostic role of Isocitrate Dehydrogenase (IDH) mutation status in adult lower grade astrocytomas was first formally presented within the WHO Classification of Tumours of the Central Nervous System (2016). IDH-mutant astrocytomas are not as common as IDH-wildtype astrocytomas but are of better prognosis. Our previous study provided an evident that IDH-mutant lower grade astrocytomas is not a homogeneous group and could be further stratified by PDGFRA amplification, CDK4 amplification and CDKN2A deletion. In this study, we detected the expressions of DNA mismatch repair (MMR) proteins (PMS2, MLH1, MSH2, MSH6) and PD-L1 by immunohistochemistry in 147 IDH-mutant lower grade astrocytomas and explored their clinical relevance. The loss of was identified in 28.6%, 1.4%, 8.8% and 13.6%, respectively. PD-L1 expression was detected in 1.4% of this cohort. Survival analysis revealed that loss of PMS2 was correlated with shorter OS (p < 0.001) and PFS (p = 0.005). Loss of PMS2 or MLH1 was associated with shorter OS (p < 0.001) and PFS (p = 0.008). In IDH-mutant lower grade astrocytomas without CDKN2A deletion, loss of PMS2 was associated with poorer OS (p < 0.001) and PFS (p = 0.001). Furthermore, among IDH-mutant lower grade astrocytomas lacking the three biomarkers (PDGFRA, CDK4 and CDKN2A), loss of PMS2 was also associated with a poorer OS (p < 0.001) and PFS (p = 0.003). Our data illustrated the potential application of MMR genes in stratification of IDH-mutant lower grade astrocytomas without PDGFRA, CDK4 and CDKN2A copy number alterations.

Underlying mechanism of the photodynamic activity of hematoporphyrin­induced apoptosis in U87 glioma cells.

Photodynamic therapy (PDT) is a relatively novel type of tumor therapy method with low toxicity and limited side­effects. The aim of the present study was to investigate the underlying mechanism and potential microRNAs (miRNAs) involved in the treatment of glioma by PDT with hematoporphyrin, a clinical photosensitizer. The photodynamic activity of hematoporphyrin on the cell viability and apoptosis of gliomas was investigated by MTT, and flow cytometry and fluorescence microscopy, respectively. Alterations in singlet oxygen and mitochondrial membrane potential were detected. The differentially expressed miRNAs and proteins were evaluated by miRNA gene chip and apoptosis­associated protein chip, respectively. The results demonstrated that cell viability significantly decreased with hematoporphyrin concentration. PDT with hematoporphyrin significantly increased cell apoptosis at a later stage, induced the content of reactive oxygen species (ROS) and decreased the mitochondrial membrane potential, indicating that PDT with hematoporphyrin inhibited cell growth via induction of radical oxygen, decreased the mitochondrial membrane potential and induced apoptosis. The upregulated miRNAs, including hsa­miR­7641, hsa­miR­9500, hsa­miR­4459, hsa­miR­21­5p, hsa­miR­663a and hsa­miR­205­5p may be important in PDT­induced cell apoptosis in glioma. Transporter 1, ATP binding cassette subfamily B member­ and nuclear factor­κB­mediated apoptosis signaling pathways were the most significant pathways. Thus, the current study presents PDT as a potential therapeutic approach for the treatment of malignant glioma, and identified miRNAs for the molecular design and development of a third­generation photosensitizer (PS).

Downregulation of miR­205 is associated with glioblastoma cell migration, invasion, and the epithelial-mesenchymal transition, by targeting ZEB1 via the Akt/mTOR signaling pathway.

Glioblastoma (GBM) is the most common type of malignant brain tumor. In spite of recent advancements in surgical techniques, chemotherapy, and radiation therapy, patients with GBM often face a dire prognosis. MicroRNAs have been shown to modulate the aggressiveness of various cancers, and have emerged as possible therapeutic agents for the management of GBM. miR­205 is dysregulated in glioma and act as a prognostic indicator. However, the role of miR­205 in the development of GBM has not been elucidated. To better understand the pathogenesis of GBM, we examine the biological significance and molecular mechanisms of miR­205 in GBM cells. Zinc finger E-box binding homeobox 1 (ZEB1) has been shown to regulate the epithelial-mesenchymal transition (EMT), which is strongly associated with GBM malignancy. In the present study, we show miR­205 expression is reduced in GBM tissues and cell lines, and ZEB1 expression is inversely correlated with miR­205 expression. We also show ZEB1 is a downstream target of miR­205 and the Akt/mTOR signaling pathway is activated when miR­205 interacts with ZEB1. Increased activity of miR­205 in GBM cells significantly inhibits migration and invasion, and prevents EMT. Furthermore, overexpression of ZEB1 partially abolishes these inhibitory effects of miR­205. We show that miR­205 negatively regulates the expression of ZEB1 in GBM, inhibits cell migration and invasion, and prevents EMT, at least in part through the inhibition of the activation of the Akt/mTOR signaling pathway. Our results indicate miR­205 may be an efficacious therapeutic agent in the treatment of GBM.

MALAT1 is a prognostic factor in glioblastoma multiforme and induces chemoresistance to temozolomide through suppressing miR-203 and promoting thymidylate synthase expression.

Glioblastoma multiforme (GBM) is the most malignant brain tumor with limited therapeutic options. Temozolomide (TMZ) is a novel cytotoxic agent used as first-line chemotherapy for GBM, however, some individual cells can't be isolated for surgical resection and show treatment-resistance, thus inducing poor prognosis. By using the HiSeq sequencing and bioinformatics methods, we identified lncRNAs showing different expression levels in TMZ-resistant and non-resistant patients. RT-qPCR was then performed in tissues and serum samples, and lncRNA MALAT1 was finally identified to show considerable discriminating potential to identify responding patients from non-responding patients. Moreover, high serum MALAT1 expression was associated with poor chemoresponse and survival in GBM patients receiving TMZ treatment. Subsequently, the TMZ resistant cell lines were established, and the CCK8 assay showed that lncRNA MALAT1 knockdown significantly reversed TMZ resistance in GBM cells. The gain and loss-function experiments revealed that miR-203 was down-regulated by MALAT1 and this interaction has reciprocal effects. Besides, thymidylate synthase (TS) mRNA was identified as a direct target of miR-203. LncRNA MALAT1 inhibition re-sensitized TMZ resistant cells through up-regulating miR-203 and down-regulating TS expression. On the other hand, MALAT1 overexpression promoted resistance by suppressing miR-203 and promoting TS expression. In conclusion, our integrated approach demonstrates that enhanced expression of lncRNA MALAT1 confers a potent poor therapeutic efficacy and inhibition of MALAT1 levels could be a future direction to develop a novel therapeutic strategy to overcome TMZ resistance in GBM patients.

Anti-hepatic Fibrosis Mechanism of Cordyceps Polysaccharide / 中国实验方剂学杂志

Hepatic fibrosis is a repair process of the liver in response to various chronic injuries. The unbalanced proliferation and decomposition of fibrous tissue in the liver causes the excessive deposition of fibrous connective tissue in the liver. Hepatic fibrosis is a common intermediate link in a variety of chronic liver diseases. In this pathological process, the interaction between cells and cytokines leads to the disorder of liver extracellular matrix metabolism, which results in excessive deposition of fibrous tissue in the liver, and eventually causes liver fibrosis. After continuous deterioration, it would gradually develop into liver cirrhosis and even liver cancer. Because liver fibrosis and liver cirrhosis can be reversed in the early stage, it is very important to control the reversible process of liver fibrosis for the prevention and treatment of liver cirrhosis and liver cancer. Cordyceps, as one of valuable medicinal fungi in China, has been given widespread attention from scientific workers, with broad pharmacological actions. Cordyceps polysaccharide is the highest content of bioactive substances in Cordyceps. Recent studies have found that it has an anti-hepatic fibrosis effect. With the application of molecular biology technology, researches on the anti-liver fibrosis mechanism of traditional Chinese medicine at home and abroad have been gradually deepened into the cellular and molecular levels. This paper will investigate the preventive effect of Cordyceps polysaccharide in terms of cell basis, cytokines, collagenase and lipid peroxidation level that are related to liver fibrosis, so as to clarify the specific action mechanism on anti-hepatic fibrosis, and provide a reference for the development of anti-hepatic fibrosis drugs.

The protective effect of QZXK in nerve injury using zebrafish model induced by MPTP / 中国药理学通报

Aim To investigate the protective effect of Qi ZhiXiaoke granules ( QZXK ) on nerve injury using zebrafish and nerve cell injury models. Methods The nerve injury model was established using wild zebrafish AB line, 72 hours after fertilization treated with 1-methyl-4-phenyl-1 , 2 , 3 , 6-four pyridine ( MPTP ) .Then QZXK of different doses were administered for three days,and the trajectory of the zebrafish behavior was recorded and analyzed. Neuroblastoma PC12 cells were incubated with different concentrations of QZXK and MPTP,and the cell viability of PC12 cells was de-tected by MTT. The mitochondrial membrane potential and expression of apoptosis related protein Caspase3 were measured by kits. Results Compared with con-trol group,MPTP reduced the movement distance of ze-brafish,and with the increase of concentration, QZXK promoted the movement distance and reversed the swimming behavior abnormality of zebrafish. Compared with control group, QZXK could inhibit the apoptosis induced by MPTP and promote the cell viability of PC12 cells with MPTP. QZXK improved the membranepotential and decreased the expression of Caspase3 . Conclusions QZXK exerts neuroprotective effect in the process of nerve injury induced by MPTP. The mechanism may be related with inhibiting apoptosis of neural cells. These experiment provides experimental and theoretical foundation for QZXK promoting cogni-tive function.

Therapy and prognosis of intracranial invasive olfactory neuroblastoma.

OBJECTIVE: There is currently no consensus on a standardized treatment strategy for olfactory neuroblastoma (ONB), especially for intracranial invasion. This purpose of this study is to explore the appropriate treatment modality and prognostic factors of intracranial invasive ONB. STUDY DESIGN: Case series with chart review. SETTING: The study was conducted at the Sun Yat-sen Memorial Hospital and the Cancer Center of Sun Yat-sen University, China. SUBJECTS AND METHODS: Twenty-five cases of intracranial invasive ONB were collected and investigated using a retrospective review analysis from patients diagnosed between 1980 and 2005. RESULTS: The 1-, 3-, and 5-year overall survival rates for the group were 55%, 46%, and 31%, respectively. The subgroups who did not receive surgical treatment had worse survival rates than those who did receive treatment. In particular, patients who did not receive any therapy did not live past 1 year. In contrast, the group of patients treated by intranasal resection in combination with radiotherapy and/or chemotherapy showed a slightly better survival rate. It is important to note that the group of patients treated by craniofacial surgery combined with radiotherapy and/or chemotherapy had a markedly favorable prognosis, with 1-, 3-, and 5-year overall survival rates of up to 100%, 88%, and 66%, respectively. CONCLUSIONS: Craniofacial surgery in combination with radiotherapy and/or chemotherapy was an effective treatment for intracranial invasive ONB. In addition, it was found that age may not be an important prognostic factor for intracranial invasive ONB; however, the rate of intracalvarial invasion was found to be a potent marker for predicting the prognosis of patients.

Simultaneous removals of NOx, HC and PM from diesel exhaust emissions by dielectric barrier discharges.

The main target of this work is to characterize the abatements of particulate matter (PM), hydrocarbons (HC) and nitrogen oxides (NO(x)) from an actual diesel exhaust using dielectric barrier discharge technology (DBD). The effects of several parameters, such as peak voltage, frequency and engine load, on the contaminant removals have been investigated intensively. The present study shows that for a given frequency, the removals of PM and HC are enhanced with the increase of peak voltage and level off at higher voltage, while in the range of higher voltages a decline of NO(x) removal efficiency is observed. For a given voltage, the maximums of specific energy density (SED) and removal efficiency are attained at resonance point. The increase of peak voltage will result in a significant decrease of energy utilization efficiency of DBD at most engine loads. Alkanes in soluble organic fraction (SOF) are more readily subjected to removals than polycyclic aromatic hydrocarbons (PAHs).

Research Progress on the Microbial L-Arabinose Isomerase / 微生物学通报

L-arabinose isomerase (L-AI) can isomerize L-arabinose and D-galactose into L-ribulose and D-tagatose, respectively, which is currently the most effective biological catalyst for D-tagatose production. The crystal structure of L-AI has been solved recently and its gene has been cloned, sequenced and overex- pressed. L-AI improved by protein engineering will be the dominant enzyme for industrial production of D-tagatose. This paper reviewed researches on protein structure and function, properties and application in D-tagatose production of L-AI, and the long-term potential development of L-AI was prospected.