According to classical immunology theory, immunoglobulin (Ig) is exclusively produced by differentiated B lymphocytes, which exhibit a typical tetrapeptide chain structure and are predominantly present on the surface of B cells and in bodily fluids. B-Ig is one of the critical effector molecules for humoral immune responses specifically recognising antigens and eliminating them. However, mounting evidence has demonstrated that Ig is widely expressed in non B lineage cells, especially malignant ones (referred to as non B-Ig). Interestingly, non B-Ig mainly resides in the cytoplasm and secretion, but to some extent on the cell surface. Furthermore non B-Ig not only displays a tetrapeptide chain structure but also shows free heavy chains and free light chains (FLCs). Additionally, Ig derived from non B cancer cell typically displays unique glycosylation modifications. Functionally, non B-Ig demonstrated diversity and versatility, showing antibody activity and cellular biological activity, such as promoting cell proliferation and survival, and it is implicated in cancer progression and some immune-related diseases, such as renal diseases.

Although V(D)J recombination and immunoglobulin (Ig) production are traditionally recognised to occur only in B lymphocytes and plasma cells, the expression of Igs in non-lymphoid cells, which we call non B cell-derived Igs (non B Igs), has been documented by growing studies. It has been demonstrated that non B-Igs can be widely expressed in most cell types, including, but not limited to, epithelial cells, cardiomyocytes, hematopoietic stem/progenitor cells, myeloid cells, and cells from immune-privileged sites, such as neurons and spermatogenic cells. In particular, malignant tumour cells express high level of IgG. Moreover, different from B-Igs that mainly localised on the B cell membrane and in the serum and perform immune defence function mainly, non B-Igs have been found to distribute more widely and play critical roles in immune defence, maintaining cell proliferation and survival, and promoting progression. The findings of non B-Igs may provide a wealthier breakthrough point for more therapeutic strategies for a wide range of immune-related diseases.

Cutaneous squamous cell carcinoma (cSCC) ranks as the second most prevalent skin tumour (excluding melanoma). However, the molecular mechanisms driving cSCC progression remain elusive. This study aimed to investigate GBP1 expression in cSCC and elucidate its potential molecular mechanisms underlying cSCC development. GBP1 expression was assessed across public databases, cell lines and tissue samples. Various assays, including clone formation, CCK8 and EdU were employed to evaluate cell proliferation, while wound healing and transwell assays determined cell migration and invasion. Subcutaneous tumour assays were conducted to assess in vivo tumour proliferation, and molecular mechanisms were explored through western blotting, immunofluorescence and immunoprecipitation. Results identified GBP1 as an oncogene in cSCC, with elevated expression in both tumour tissues and cells, strongly correlating with tumour stage and grade. In vitro and in vivo investigations revealed that increased GBP1 expression significantly enhanced cSCC cell proliferation, migration and invasion. Mechanistically, GBP1 interaction with SP1 promoted STAT3 activation, contributing to malignant behaviours. In conclusion, the study highlights the crucial role of the GBP1/SP1/STAT3 signalling axis in regulating tumour progression in cSCC. These findings provide valuable insights into the molecular mechanisms of cSCC development and offer potential therapeutic targets for interventions against cSCC.

BACKGROUND: A series of studies have demonstrated the emerging involvement of transfer RNA (tRNA) processing during the progression of tumours. Nevertheless, the roles and regulating mechanisms of tRNA processing genes in neuroblastoma (NB), the prevalent malignant tumour outside the brain in children, are yet unknown.
METHODS: Analysis of multi-omics results was conducted to identify crucial regulators of downstream tRNA processing genes. Co-immunoprecipitation and mass spectrometry methods were utilised to measure interaction between proteins. The impact of transcriptional regulators on expression of downstream genes was measured by dual-luciferase reporter, chromatin immunoprecipitation, western blotting and real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) methods. Studies have been conducted to reveal impact and mechanisms of transcriptional regulators on biological processes of NB. Survival differences were analysed using the log-rank test.
RESULTS: c-Myc was identified as a transcription factor driving tRNA processing gene expression and subsequent malate-aspartate shuttle (MAS) in NB cells. Mechanistically, c-Myc directly promoted the expression of glutamyl-prolyl-tRNA synthetase (EPRS) and leucyl-tRNA synthetase (LARS), resulting in translational up-regulation of glutamic-oxaloacetic transaminase 1 (GOT1) as well as malate dehydrogenase 1 (MDH1) via inhibiting general control nonrepressed 2 or activating mechanistic target of rapamycin signalling. Meanwhile, lamin A (LMNA) inhibited c-Myc transactivation via physical interaction, leading to suppression of MAS, aerobic glycolysis, tumourigenesis and aggressiveness. Pre-clinically, lobeline was discovered as a LMNA-binding compound to facilitate its interaction with c-Myc, which inhibited aminoacyl-tRNA synthetase expression, MAS and tumour progression of NB, as well as growth of organoid derived from c-Myc knock-in mice. Low levels of LMNA or elevated expression of c-Myc, EPRS, LARS, GOT1 or MDH1 were linked to a worse outcome and a shorter survival time of clinical NB patients.
CONCLUSIONS: These results suggest that targeting c-Myc transactivation by LMNA inhibits tRNA processing essential for MAS and tumour progression.

Angiogenin (ANG) is a specialised secreted ribonuclease, also known as RNase5, that is widely expressed in vertebrates. ANG dysregulation is closely associated with the development of breast, nasopharyngeal, and lung cancers. In recent years, studies have found that ANG not only induces neovascularisation by activating endothelial cells, but also plays a regulatory role in the plasticity of cancer cells. Cellular plasticity plays pivotal roles in cancer initiation, progression, migration, therapeutic resistance, and relapse. Therefore, it is a promising biomarker for cancer diagnosis, prognostic evaluation, and therapy. This review summarises the current knowledge regarding the roles and clinical applications of ANG in cancer development and progression.

Steroid receptor coactivator-1 (SRC-1, also known as NCOA1) frequently functions as a transcriptional coactivator by directly binding to transcription factors and recruiting to the target gene promoters to promote gene transcription by increasing chromatin accessibility and promoting the formation of transcriptional complexes. In recent decades, various biological and pathological functions of SRC-1 have been reported, especially in the context of tumorigenesis. SRC-1 is a facilitator of the progression of multiple cancers, including breast cancer, prostate cancer, gastrointestinal cancer, neurological cancer, and female genital system cancer. The emerging multiorgan oncogenic role of SRC-1 is still being studied and may not be limited to only steroid hormone-producing tissues. Growing evidence suggests that SRC-1 promotes target gene expression by directly binding to transcription factors, which may constitute a novel coactivation pattern independent of AR or ER. In addition, the antitumour effect of pharmacological inhibition of SRC-1 with agents including various small molecules or naturally active compounds has been reported, but their practical application in clinical cancer therapy is very limited. For this review, we gathered typical evidence on the oncogenic role of SRC-1, highlighted its major collaborators and regulatory genes, and mapped the potential mechanisms by which SRC-1 promotes primary tumour progression.

BACKGROUND: Extracellular vesicles (EVs) participate in cancer development via cell-to-cell communication. Long non-coding RNAs (lncRNAs), one component of EVs, can play an essential role in non-small-cell lung cancer (NSCLC) through EV-mediated delivery.
METHODS: The NSCLC-associated lncRNA AL139294.1 in EVs was identified via lncRNA microarray analysis. The role of AL139294.1 in NSCLC was examined in vitro and in vivo. Confocal microscopy was used to observe the encapsulation of AL139294.1 into EVs and its transport to recipient cells. A co-culture device was used to examine the effects of transported AL139294.1 on the oncogenic behaviour of recipient cells. Dual-luciferase reporter assay was performed to verify the direct interaction of miR-204-5p with AL139294.1 and bromodomain-containing protein 4 (BRD4). AL139294.1 and miR-204-5p in EVs were quantified using quantitative polymerase chain reaction. Receiver operating characteristic analyses were conducted to evaluate the diagnostic efficiency.
RESULTS: The lncRNA AL139294.1 in EVs promoted NSCLC progression in vitro and in vivo. After AL139294.1 was encapsulated into EVs and transported to recipient cells, it promoted the cells\' proliferation, migration, and invasion abilities by competitively binding with miR-204-5p to regulate BRD4, leading to the activation of the Wnt and NF-κB2 pathways. Additionally, the expression of serum lncRNA AL139294.1 in EVs was increased, whereas miR-204-5p in EVs was decreased in NSCLC. High levels of lncRNA AL139294.1 and low levels of miR-204-5p in EVs were associated with advanced pathological staging, lymph node metastasis, and distant metastasis, underscoring their promising utility for distinguishing between more and less severe manifestations of the disease.
CONCLUSIONS: This study reveals a novel lncRNA in EVs associated with NSCLC, namely, AL139294.1, providing valuable insights into the development of NSCLC and introducing potential diagnostic biomarkers for NSCLC.

BACKGROUND: The role of Tousled-like kinase 1 (TLK1) in in gastric cancer (GC) remains unclear.
OBJECTIVE: To investigate the expression, biological function, and underlying mechanisms of TLK1 in GC.
METHODS: We measured TLK1 protein expression levels and localized TLK1 in GC cells and tissues by western blot and immunofluorescence, respectively. We transfected various GC cells with lentiviruses to create TLK1 overexpression and knockdown lines and established the functional roles of TLK1 through in vitro colony formation, 5-ethynyl-2`-deoxyuridine, and Transwell assays as well as flow cytometry. We applied bioinformatics to elucidate the signaling pathways associated with TLK1. We performed in vivo validation of TLK1 functions by inducing subcutaneous xenograft tumors in nude mice.
RESULTS: TLK1 was significantly upregulated in GC cells and tissues compared to their normal counterparts and was localized mainly to the nucleus. TLK1 knockdown significantly decreased colony formation, proliferation, invasion, and migration but increased apoptosis in GC cells. TLK1 overexpression had the opposite effects. Bioinformatics revealed, and subsequent experiments verified, that the tumor growth factor-beta signaling pathway was implicated in TLK1-mediated GC progression. The in vivo assays confirmed that TLK1 promotes tumorigenesis in GC.
CONCLUSIONS: The findings of the present study indicated that TLK1 plays a crucial role in GC progression and is, therefore, promising as a therapeutic target against this disease.

As the most prominent RNA modification, N6-methyladenosine (m6 A) participates in the regulation of tumour initiation and progression. Circular RNAs (circRNAs) also play crucial roles in ubiquitous life processes. Whether circRNAs are required for m6 A regulation in renal cell carcinoma (RCC) remains unclear. Meta-analysis and bioinformatics identified that IGF2BP3 was upregulated in RCC and indicated a worse prognosis. IGF2BP3 significantly promoted RCC progression in vitro and in vivo. Mechanistically, circRARS bound to KH1-KH2 domains of IGF2BP3 to enhance m6 A modification recognition. A 12-nt sequence (GUCUUCCAGCAA) was proven to be the IGF2BP3-binding site of circRARS. Additionally, CAPN15, CD44, HMGA2, TNRC6A and ZMIZ2 were screened to be the target genes regulated by the IGF2BP3/circRARS complex in an m6 A-dependent manner. Stabiliser proteins, including HuR, Matrin3 and pAbPC1, were recruited by circRARS, thereby increasing the mRNA stability of the forementioned five target genes. Consequently, the IGF2BP3/circRARS complex facilitated the lipid accumulation of RCC cells and promoted sunitinib resistance via target genes. circRARS synergised with IGF2BP3 to facilitate m6 A recognition, thereby promoting RCC progression. Thus, IGF2BP3 could be a potential biomarker for RCC diagnosis and prognosis and a therapeutic target.

Oesophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumours with high morbidity and mortality. Although surgery, radiotherapy and chemotherapy are common treatment options available for oesophageal cancer, the 5-year survival rate remains low after treatment. On the one hand, many oesophageal cancers are are discovered at an advanced stage and, on the other hand, treatment resistance is a major obstacle to treating locally advanced ESCC. Cancer-associated fibroblasts (CAFs), the main type of stromal cell in the tumour microenvironment, enhance tumour progression and treatment resistance and have emerged as a major focus of study on targeted therapy of oesophageal cancer.With the aim of providing potential, prospective targets for improving therapeutic efficacy, this review summarises the origin and activation of CAFs and their specific role in regulating tumour progression and treatment resistance in ESCC. We also emphasize the clinical potential and emerging trends of ESCC CAFs-targeted treatments.