HOXB9 enhances the ability of lung cancer cells to penetrate the blood-brain barrier

A Review of Recent Advances in the Molecular Mechanisms Underlying Brain Metastasis in Lung Cancer

Brain metastasis from lung cancer is a prevalent mode of treatment failure associated with a poor prognosis. The incidence of brain metastasis has recently shown a dramatic increase. The early detection and risk stratification of lung cancer-related brain metastasis would be highly advantageous for patients. However, our current knowledge and comprehension of the underlying mechanisms driving brain metastasis in lung cancer pose significant challenges. This review summarizes the mechanisms underlying brain metastasis, focusing on the intricate interplay between lung cancer-derived tumor cells and the unique characteristics of the brain, recent advancements in the identification of driver genes, concomitant genes, epigenetic features, including miRNAs and long noncoding RNAs, as well as the molecular characterization of brain metastasis originating from other organs, which may further enhance risk stratification and facilitate precise treatment strategies.

HOXB9 promotes laryngeal squamous cell carcinoma progression by upregulating MMP12

Transcriptional factor HOXB9, a part of the HOX gene family, plays a crucial role in the development of diverse cancer types. This study aimed to elucidate the regulatory mechanism of HOXB9 on the proliferation and invasion of laryngeal squamous cell carcinoma (LSCC) cells to provide guidance for the development and prognosis of LSCC. The CRISPR/Cas9 method was employed in LSCC cell lines to knock out the HOXB9 gene and validate its effects on the proliferation, migration, invasion, and regulation of LSCC cells. CCK-8 and flow cytometry were used to detect cell viability and proliferation; Tunnel was used to detect cell apoptosis, and transwell was used to detect cell migration and invasion. The effect of HOXB9 on tumor growth was tested in nude mice. The downstream target genes regulated by HOXB9 were screened by microarray analysis and verified by Western blotting, immunohistochemistry, chromatin immunoprecipitation, and double-luciferase reporter assays. The current research investigated molecular pathways governed by HOXB9 in the development of LSCC. Additionally, both laboratory- and living-organism-based investigations revealed that disrupting the HOXB9 gene through the CRISPR/CAS9 mechanism restrained cellular growth, movement, and infiltration, while enhancing cellular apoptosis. Detailed analyses of LSCC cell strains and human LSCC samples revealed that HOXB9 promoted LSCC progression by directly elevating the transcriptional activity of MMP12. HOXB9 could influence changes in LSCC cell functions, and the mechanism of action might be exerted through its downstream target gene, MMP12.

Establishment, characterization, and drug screening of low-passage patient individual non-small cell lung cancer in vitro models including the rare pleomorphic subentity

Introduction

For pre-clinical drug development and precision oncology research, robust cancer cell models are essential. Patient-derived models in low passages retain more genetic and phenotypic characteristics of their original tumors than conventional cancer cell lines. Subentity, individual genetics, and heterogeneity greatly influence drug sensitivity and clinical outcome.

Materials and methods

Here, we report on the establishment and characterization of three patient-derived cell lines (PDCs) of different subentities of non-small cell lung cancer (NSCLC): adeno-, squamous cell, and pleomorphic carcinoma. The in-depth characterization of our PDCs included phenotype, proliferation, surface protein expression, invasion, and migration behavior as well as whole-exome and RNA sequencing. Additionally, in vitro drug sensitivity towards standard-of-care chemotherapeutic regimens was evaluated.

Results

The pathological and molecular properties of the patients' tumors were preserved in the PDC models HROLu22, HROLu55, and HROBML01. All cell lines expressed HLA I, while none were positive for HLA II. The epithelial cell marker CD326 and the lung tumor markers CCDC59, LYPD3, and DSG3 were also detected. The most frequently mutated genes included TP53, MXRA5, MUC16, and MUC19. Among the most overexpressed genes in tumor cells compared to normal tissue were the transcription factors HOXB9, SIM2, ZIC5, SP8, TFAP2A, FOXE1, HOXB13, and SALL4; the cancer testis antigen CT83; and the cytokine IL23A. The most downregulated genes on the RNA level encode the long non-coding RNA LANCL1-AS1, LINC00670, BANCR, and LOC100652999; the regulator of angiogenesis ANGPT4; the signaling molecules PLA2G1B and RS1; and the immune modulator SFTPD. Furthermore, neither pre-existing therapy resistances nor drug antagonistic effects could be observed.

Conclusion

In summary, we successfully established three novel NSCLC PDC models from an adeno-, a squamous cell, and a pleomorphic carcinoma. Of note, NSCLC cell models of the pleomorphic subentity are very rare. The detailed characterization including molecular, morphological, and drug-sensitivity profiling makes these models valuable pre-clinical tools for drug development applications and research on precision cancer therapy. The pleomorphic model additionally enables research on a functional and cell-based level of this rare NCSLC subentity.

Homeobox B9 Promotes the Progression of Hepatocellular Carcinoma via TGF-β1/Smad and ERK1/2 Signaling Pathways

Objectives

Homeobox B9 (HOXB9), a homeodomain-containing transcription factor, may play a role in hepatocellular carcinoma (HCC) progression. However, the exact mechanisms underlying its action remain unclear. Materials and methods. Immunohistochemistry was used to investigate the expression of HOBX9 and its prognostic values in HCC patients. HCC cells were transfected with pBabe-HOXB9 and shHOXB9 plasmids, and MTT assay, Transwell assays, and xenograft mouse models were employed to determine the effects of HOXB9 on HCC cell proliferation, migration, and invasion in vitro and in vivo. The biological mechanisms involved in the role of HOXB9 were determined with Western blot and RT-qPCR methods.

Results

HOXB9 expression was significantly increased in HCC tissues and cell lines. Patients with higher HOXB9 levels were associated with poor prognosis. Overexpression of HOXB9 in BEL-7405 cells promoted proliferation, migration, and invasion, whereas knockdown of HOXB9 in HepG2 cells significantly reduced cell proliferation, migration, and invasion abilities. Mechanically, a positive correlation was found between HOXB9 expression and transforming growth factor-β1 (TGF-β1) and extracellular signal-regulated kinase (ERK)1/2 pathway in HCC tissues. HOXB9 overexpression stimulated TGF-β1/Smads signaling pathway in BEL-7405 cells. In contrast, HOXB9 knockdown inhibited the TGF-β1/Smads signaling pathway in HepG2 cells. In addition, the treatment with TGF-β1 inhibitor, LY364947, significantly reserved HOXB9 overexpression-induced cell proliferation, migration, and invasion abilities.

Conclusions

These findings validated that HOXB9 promoted proliferation, migration, and invasion in HCC cells by stimulating the TGF-β1/Smads and ERK1/2 signaling pathway. HOXB9 could be a promising prognostic biomarker and a potential therapeutic target in HCC.

The AMPK-HOXB9-KRAS axis regulates lung adenocarcinoma growth in response to cellular energy alterations

HOXB9 is an important transcription factor associated with unfavorable outcomes in patients with lung adenocarcinoma (LUAD). However, its degradation mechanism remains unclear. Here, we show that HOXB9 is a substrate of AMP kinase alpha (AMPKα). AMPK mediates HOXB9 T133 phosphorylation and downregulates the level of HOXB9 in mice and LUAD cells. Mechanistically, phosphorylated HOXB9 promoted E3 ligase Praja2-mediated HOXB9 degradation. Blocking HOXB9 phosphorylation by depleting AMPKα1/2 or employing the HOXB9 T133A mutant promoted tumor cell growth in cell culture and mouse xenografts via upregulation of HOXB9 and KRAS that is herein identified as a target of HOXB9. Clinically, AMPK activation levels in LUAD samples were positively correlated with pHOXB9 levels; higher pHOXB9 levels were associated with better survival of patients with LUAD. We thus present a HOXB9 degradation mechanism and demonstrate an AMPK-HOXB9-KRAS axis linking glucose-level-regulated AMPK activation to HOXB9 stability and KRAS gene expression, ultimately controlling LUAD progression.

Recent Multiomics Approaches in Endometrial Cancer

Endometrial cancer is the most common gynecological cancers in developed countries. Many of the mechanisms involved in its initiation and progression remain unclear. Analysis providing comprehensive data on the genome, transcriptome, proteome, and epigenome could help in selecting molecular markers and targets in endometrial cancer. Multiomics approaches can reveal disturbances in multiple biological systems, giving a broader picture of the problem. However, they provide a large amount of data that require processing and further integration prior to analysis. There are several repositories of multiomics datasets, including endometrial cancer data, as well as portals allowing multiomics data analysis and visualization, including Oncomine, UALCAN, LinkedOmics, and miRDB. Multiomics approaches have also been applied in endometrial cancer research in order to identify novel molecular markers and therapeutic targets. This review describes in detail the latest findings on multiomics approaches in endometrial cancer.