STNM1 in human cancers: role, function and potential therapy sensitizer

STMN1 belongs to the stathmin gene family, it encodes a cytoplasmic phosphorylated protein, stathmin1, which is commonly observed in vertebrate cells. STMN1 is a structural microtubule-associated protein (MAP) that binds to microtubule protein dimers rather than microtubules, with each STMN1 binding two microtubule protein dimers and preventing their aggregation, leading to microtubule instability. STMN1 expression is elevated in a number of malignancies, and inhibition of its expression can interfere with tumor cell division. Its expression can change the division of tumor cells, thereby arresting cell growth in the G2/M phase. Moreover, STMN1 expression affects tumor cell sensitivity to anti-microtubule drug analogs, including vincristine and paclitaxel. The research on MAPs is limited, and new insights on the mechanism of STMN1 in different cancers are emerging. The effective application of STMN1 in cancer prognosis and treatment requires further understanding of this protein. Here, we summarize the general characteristics of STMN1 and outline how STMN1 plays a role in cancer development, targeting multiple signaling networks and acting as a downstream target for multiple microRNAs, circRNAs, and lincRNAs. We also summarize recent findings on the function role of STMN1 in tumor resistance and as a therapeutic target for cancer.

Identification of a prognosis-related ceRNA network in cholangiocarcinoma and potentially therapeutic molecules using a bioinformatic approach and molecular docking

Cholangiocarcinoma (CCA) is a highly malignant disease with a poor prognosis, and mechanisms of initiation and development are not well characterized. It is long noncoding RNAs (lncRNAs) acting as miRNA decoys to regulate cancer-related RNAs in competing endogenous RNA (ceRNA) networks that suggest a possible molecular mechanism in CCA. The current study aims to find potential prognosis biomarkers and small molecule therapeutic targets based on the construction of a CCA prognosis-related ceRNA network. A transcriptome dataset for CCA was downloaded from the TCGA database. Differentially expressed lncRNAs (DElncRNAs), DEmiRNAs and DEmRNAs were identified based on the differential expression and a DEceRNA network was constructed using predicted miRNA-lncRNA and miRNA-mRNA interactions. Heat maps, PCA analysis, and Pathway enrichment analysis and GO enrichment analysis were conducted. The prognostic risk model and molecular docking were constructed based on identified key ceRNA networks. A DElncRNA-miRNA-mRNAs network consisting of 434 lncRNA-miRNA pairs and 284 miRNA-mRNA pairs with 200 lncRNAs, 21 miRNAs, and 245 mRNAs was constructed. There were three lncRNAs (AC090772.1, LINC00519, and THAP7-AS1) and their downstream mRNAs (MECOM, MBNL3, RCN2) screened out as prognostic factors in CAA. Three key networks (LINC00519/ hsa-mir-22/ MECOM, THAP7-AS1/hsa-mir-155/MBNL3, and THAP7-AS1/hsa-mir-155/RCN2) were identified based on binding sites prediction and survival analysis. A prognostic risk model was established with a good predictive ability (AUC = 0.66–0.83). Four anticancer small molecules, MECOM and 17-alpha-estradiol (−7.1 kcal/mol), RCN2 and emodin (−8.3 kcal/mol), RCN2 and alpha-tocopherol (−5.6 kcal/mol), and MBNL3 and 17-beta-estradiol (−7.1 kcal/mol) were identified. Based on the DEceRNA network and Kaplan–Meier survival analysis, we identified three important ceRNA networks associated with the poor prognosis of CCA. Four anti-cancer small molecules were screened out by computer-assisted drug screening as potential small molecules for the treatment of CCA. This study provides theoretical support for the development of ceRNA network-based drugs to improve the prognosis of CCA.

The emerging roles of KPNA2 in cancer

Karyopherin α2 (KPNA2, also known as importinα-1), a member of the nuclear transporter family, is involved in the nucleocytoplasmic transport pathway of a variety of tumor-associated proteins. Recent studies have found that KPNA2 is overexpressed in various cancers, which is associated with poor prognosis. In addition, it has been shown to promote tumor formation and progression by participating in cell differentiation, proliferation, apoptosis, immune response, and viral infection. It is indicated that KPNA2 also plays an important role in the diagnosis, treatment and prognosis of tumors. Herein, we provide an overview of the function and mechanism of KPNA2 in cancer and the prospects in the diagnosis and treatment of cancer. In the future, KPNA2 provides new ideas for the early diagnosis of malignant tumors, the development of molecularly targeted drugs, and prognosis evaluation.

Pancreaticobiliary maljunction and congenital biliary dilatation

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. Because the action of the sphincter of Oddi does not regulate the function of the pancreaticobiliary junction in patients with pancreaticobiliary maljunction, two-way regurgitation occurs. Reflux of pancreatic juice into the biliary tract is associated with a high incidence of biliary cancer. Biliary carcinogenesis in patients with pancreaticobiliary maljunction is thought to follow the hyperplasia, dysplasia, then carcinoma sequence due to chronic inflammation caused by pancreatobiliary reflux. Pancreaticobiliary maljunction is diagnosed when an abnormally long common channel is evident on imaging studies. Congenital biliary dilatation involves both local dilatation of the extrahepatic bile duct, including the common bile duct, and pancreaticobiliary maljunction. Extrahepatic bile duct resection is the standard surgery for congenital biliary dilatation. However, complete excision of the intrapancreatic bile duct and removal of stenoses of the hepatic ducts are necessary to prevent serious complications after surgery.

Carcinoma of the Papilla of Vater after Diversion Operation for Pancreaticobiliary Maljunction

Pancreaticobiliary maljunction (PBM) is a congenital malformation that is associated with biliary cancer development. When patients are diagnosed with PBM, a diversion operation is recommended. Although a risk remains for developing residual bile duct carcinoma following diversion, the development of a carcinoma of the ampulla of Vater after a diversion operation for PBM is rare. We present a treated case of carcinoma of the ampulla of Vater after a diversion operation for PBM. A 65-year-old woman presented with abdominal pain. She had undergone extrahepatic bile duct resection and cholecystectomy 2 years 9 months previously for the treatment of type Ic PBM according to the Todani classification. At the current admission for evaluation of the abdominal pain, computed tomography and magnetic resonance imaging showed only dilation of the main pancreatic duct. However, gastrointestinal endoscopy showed a tumor at the papilla of Vater, and biopsy revealed adenocarcinoma of the papilla of Vater. We performed pylorus-preserving pancreaticoduodenectomy, and the pathological diagnosis was moderately differentiated tubular adenocarcinoma of the papilla of Vater with no metastasis to the lymph nodes. The patient remained in good health for 3 years postoperatively. Carcinoma of the papilla of Vater after a diversion operation for PBM is rare. In this case, a diagnosis could not be made by computed tomography or magnetic resonance imaging; the definitive diagnosis was obtained with gastrointestinal endoscopy. Careful postoperative follow-up with gastrointestinal endoscopy in addition to imaging examination may be needed after a diversion operation for PBM.

High STMN1 level is associated with chemo-resistance and poor prognosis in gastric cancer patients

Background:

Stathmin1 (STMN1) is a cytosolic phosphoprotein that regulates cellular microtubule dynamics and is known to have oncogenic activity. Despite several reports, its roles in gastric cancer (GC) remain unclear owing to a lack of analyses of highly metastatic cases. This study aimed to investigate STMN1 as a prognostic and predictive indicator of response to paclitaxel therapy in patients with GC, including inoperable cases.

Methods:

Immunohistochemical analysis of STMN1 was performed on both operable (n=95) and inoperable GC (n=61) samples. The roles of STMN1 in cancer cell proliferation and sensitivity to a microtubule-targeting drug, paclitaxel, were confirmed by knockdown experiments using GC cell lines.

Results:

Multivariate and Kaplan–Meier analyses demonstrated that high STMN1 was predictive of poor prognosis in both the groups. In the operable cohort, STMN1 expression correlated with cancer curability, recurrence, and resistance to adjuvant therapy. A correlation with paclitaxel resistance was observed in inoperable cases. Knockdown of STMN1 in GC cell lines inhibited proliferation and sensitised the cells to paclitaxel by enhancing apoptosis.

Conclusions:

STMN1 is a possible biomarker for paclitaxel sensitivity and poor prognosis in GC and could be a novel therapeutic target in metastatic GC.