Targeting gallbladder cancer: a pathway based perspective

IGF2BP3 drives gallbladder cancer progression by m6A-modified CLDN4 and inducing macrophage immunosuppressive polarization

INTRODUCTION

N6-methyladenosine (m6A) is an emerging epigenetic modification, which plays a crucial role in the development of cancer. Nevertheless, the underlying mechanism of m6A-associated proteins and m6A modification in gallbladder cancer remains largely unknown.

MATERIALS AND METHODS

The Gene Expression Omnibus database and tissue microarray were used to identify the key m6A-related gene in gallbladder cancer. The function and mechanism of IGF2BP3 were further investigated by knockdown and overexpression techniques in vitro and in vivo.

RESULTS

We found that IGF2BP3 was elevated and correlated with poor prognosis in gallbladder cancer, which can be used as an independent prognostic factor for gallbladder cancer. IGF2BP3 accelerated the proliferation, invasion and migration of gallbladder cancer cells in vitro and in vivo. Mechanistically, IGF2BP3 interacted with and augmented the stability of CLDN4 mRNA by m6A modification. Enhancement of CLDN4 reversed the inhibitory effect of IGF2BP3 deficiency on gallbladder cancer. Furthermore, we demonstrated that IGF2BP3 promotes the activation of NF-κB signaling pathway by up-regulation of CLDN4. Overexpression of IGF2BP3 in gallbladder cancer cells obviously promoted the polarization of immunosuppressive phenotype in macrophages. Besides, Gallbladder cancer cells-derived IGF2BP3 up-regulated the levels of STAT3 in M2 macrophages, and promoted M2 polarization.

CONCLUSIONS

We manifested IGF2BP3 promotes the aggressive phenotype of gallbladder cancer by stabilizing CLDN4 mRNA in an m6A-dependent manner and induces macrophage immunosuppressive polarization, which might offer a new theoretical basis for against gallbladder cancer.

Proteomic analysis identifies dysregulated proteins and associated molecular pathways in a cohort of gallbladder cancer patients of African ancestry

BACKGROUND

Gallbladder cancer (GBC) is a lethal cancer with a poor prognosis. The lack of specific and sensitive biomarkers results in delayed diagnosis with most patients presenting at late stages of the disease. Furthermore, there is little known about the molecular mechanisms associated with GBC, especially in patients of African ancestry. This study aimed to determine dysregulated proteins in South African GBC patients to identify potential mechanisms of the disease progression and plausible biomarkers.

METHODS

Tissues (27 GBC, 13 Gallstone disease, and 5 normal tissues) and blood plasma (54 GBC and 73 Benign biliary pathology) were obtained from consenting patients. Protein extraction was performed on all tissues and liquid chromatography-mass spectrometry was used for proteomic profiling. A project-specific spectral library was built using the Pulsar search algorithm. Principal component and Spearman's rank correlation analyses were performed using PAST (V4.07b). Pathway and Network analyses were conducted using REACTOME (v3.7) and stringAPP (v1.7.0), respectively.

RESULTS

In the tissue sample group, there were 62 and 194 dysregulated proteins in GBC compared to normal and gallstone groups, respectively. In the plasma group, there were 33 altered proteins in GBC compared to the benign biliary pathology group. We found 9 proteins (APOA1, APOA2, RET4, TTR, HEMO, HBB, HBA, PIGR, and APOE) to be commonly dysregulated in both tissue and plasma. Furthermore, a subset analysis demonstrated that 2 proteins, S100A8 and S100A9, were downregulated in GBC patients with GD history compared to those without. Pathway analysis showed that the dysregulated proteins in GBC patients were enriched in pathways involved in smooth muscle contraction, metabolism, ECM organization, and integrin cell surface interactions.

CONCLUSION

The identified dysregulated proteins help in understanding GBC molecular mechanisms in our patient group. Furthermore, the alteration of specific proteins in both tissue and plasma samples suggests their potential utility as biomarkers of GBC in this sample cohort.

Unravelling of the comparative Transcriptomic Profile of Gallbladder Cancer using mRNA sequencing

BACKGROUND

Gallbladder cancer (GBC) represents a wide geographical diversity as well as heterogeneity in clinical and genomic landscape. There seems to be little progress in the development of diagnostic biomarkers, targeted therapies or individualized approaches to GBC management. In this study, we investigated the whole transcriptome profile of GBC patients using RNA sequencing and identified key genes and pathways associated with gallbladder cancer using bioinformatics.

METHODOLOGY

A total of 10 cases of GBC were collected and sequenced. The raw reads of the gallbladder sample was compared with the gallbladder normal control (SRA Database ID: ERX288537: HPA RNA-seq normal tissues gallbladder). Using Gene ontology analysis the differentially expressed genes were categorized into the biological pathway, cellular component, and molecular function. Pathway enrichment analyses, protein-protein interaction, transcription factor and miRNA interaction that regulate the expression of hub genes were conducted using bioinformatics tool.

RESULTS

A total of 954 differentially expressed mRNA transcripts were identified, including overexpression of REG4, TMEM238, S100A2, LYPD2, and KRT17, as well as underexpressed genes like CCKAR, IGSF10, CHRM2, CRISP3, and FGF19. Enrichment analysis showed the metabolic pathways to be the top five cancer pathways in gallbladder carcinogenesis besides PI3k-Akt signalling pathway, cAMP signalling pathway, miRNAs in cancer, and cell adhesion profile of GBC.

CONCLUSIONS

CCKAR, CDKN2A and LRRK2 were found to be most involved genes in its progression and development through different regulatory pathways. Further, most of the genes were significantly involved in PI3k-Akt, Wnt and hedgehog signaling pathways which have a key role in gallbladder cancer development.