Background: The number of clinical studies evaluating the benefit of cytokine-induced killer cell (CIK) therapy, an adoptive immunotherapy, for colorectal cancer (CRC) is increasing. In many of these trials, CIK therapy was coadministered with conventional cancer therapy. The aim of this review is to systematically assess the available literature, in which the majority were only in Chinese, on CIK therapy for the management of CRC using meta-analysis and to identify parameters associated with successful CIK therapy implementation. Methods: Prospective and retrospective clinical studies which compared CIK therapy to non-CIK therapy in patients with CRC were searched for electronically on MEDLINE, Embase, China National Knowledge Infrastructure, and Wanfang Data databases. The clinical endpoints of overall survival (OS), progression-free survival (PFS), OS and PFS rates, overall response rate (ORR), and toxicity were meta-analyzed using HR and relative ratio (RR), and subgroup analyses were performed using chi-square (χ²) test and I-squared (I²) statistics for study design, disease stage, cotherapy type, and timing of administration. Results: In total, 70 studies involving 6743 patients were analyzed. CIK therapy was favored over non-CIK therapy for OS (HR=0.59, 95% CI: 0.53 to 0.65), PFS (HR=0.55, 95% CI: 0.47 to 0.63), and ORR (RR=0.65, 95% CI: 0.57 to 0.74) without increasing toxicity (HR=0.59, 95% CI: 0.16 to 2.25). Subgroup analyses on OS and PFS by study design (randomized vs non-randomized study design), disease stage (Stage I–III vs Stage IV), cotreatment with dendritic cells (DCs) (CIK vs DC-CIK therapy), or timing of therapy administration (concurrent vs sequential with coadministered anticancer therapy) also showed that the clinical benefit of CIK therapy was robust in any subgroup analysis. Furthermore, cotreatment with DCs did not improve clinical outcomes over CIK therapy alone. Conclusion: Compared with standard therapy, patients who received additional CIK cell therapy had favorable outcomes without increased toxicity, warranting further investigation into CIK therapy for the treatment of CRC.

The breast tissue microbiome has been increasingly recognized as a potential contributor to breast cancer development and progression. However, inconsistencies in microbial composition across studies have hindered the identification of definitive microbial signatures. We conducted a systematic review and meta-analysis of 11 studies using 16S rRNA sequencing to characterize the bacterial microbiome in 1260 fresh breast tissue samples, including normal, mastitis-affected, benign, cancer-adjacent, and cancerous tissues. Studies published until 31 December 2023 were included if they analyzed human breast tissue using Illumina short-read 16S rRNA sequencing with sufficient metadata, while non-human samples, non-breast tissues, non-English articles, and those lacking metadata or using alternative sequencing methods were excluded. We also incorporated microbiome data from The Cancer Genome Atlas breast cancer (TCGA-BRCA) cohort to enhance our analyses. Our meta-analysis identified Proteobacteria, Firmicutes, Actinobacteriota, and Bacteroidota as the dominant phyla in breast tissue, with Staphylococcus and Corynebacterium frequently detected across studies. While microbial diversity was similar between cancer and cancer-adjacent tissues, they both exhibited a lower diversity compared to normal and mastitis-affected tissues. Variability in bacterial genera was observed across primer sets and studies, emphasizing the need for standardized methodologies in microbiome research. An analysis of TCGA-BRCA data confirmed the dominance of Staphylococcus and Corynebacterium, which was associated with breast cancer proliferation-related gene expression programs. Notably, high Staphylococcus abundance was associated with a 4.1-fold increased mortality risk. These findings underscore the potential clinical relevance of the breast microbiome in tumor progression and emphasize the importance of methodological consistency. Future studies to establish causal relationships, elucidate underlying mechanisms, and assess microbiome-targeted interventions are warranted.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Perhexiline, a prophylactic anti-anginal drug, has been reported to have anti-tumour effects both in vitro and in vivo. Perhexiline as used clinically is a 50:50 racemic mixture ((R)-P) of (−) and (+) enantiomers. It is not known if the enantiomers differ in terms of their effects on cancer. In this study, we examined the cytotoxic capacity of perhexiline and its enantiomers ((−)-P and (+)-P) on CRC cell lines, grown as monolayers or spheroids, and patient-derived organoids. Treatment of CRC cell lines with (R)-P, (−)-P or (+)-P reduced cell viability, with IC₅₀ values of ~4 µM. Treatment was associated with an increase in annexin V staining and caspase 3/7 activation, indicating apoptosis induction. Caspase 3/7 activation and loss of structural integrity were also observed in CRC cell lines grown as spheroids. Drug treatment at clinically relevant concentrations significantly reduced the viability of patient-derived CRC organoids. Given these in vitro findings, perhexiline, as a racemic mixture or its enantiomers, warrants further investigation as a repurposed drug for use in the management of CRC.

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited therapeutic options and inconsistent response to immune checkpoint inhibitors (ICIs). Emerging evidence indicates that tumor-associated bacteria may shape immune signaling and alter immunotherapy outcomes. Here, we investigated whether Staphylococcus aureus invades TNBC cells, persists intracellularly, and modulates PD-L1 expression. Methods: Using eFluor450-labeled S. aureus for flow cytometry, gentamicin protection assays, CFU quantification, and transmission electron microscopy, we assessed bacterial uptake and persistence in six TNBC cell lines and a non-tumorigenic control. PD-L1, TLR2, and STAT1 activation were evaluated after infection or TLR2 ligand treatment ± IFN-γ. Results: At multiplicity of infection (MOI) of 10, S. aureus internalized into 67% of MDA-MB-468 and 54% of MDA-MB-231, with intermediate uptake in Hs578T (27%) and BT-549 (24%) and only 0.5–9% in low-uptake lines (MDA-MB-453, CAL-51, MCF-12A). High-uptake lines exhibited marked cytotoxicity and reduced proliferation, with MDA-MB-468 showing an 82% drop in viability at 2 h and a 74% decrease after 5 d, whereas low-uptake lines showed minimal impact. Persistence lasted >7 d in MDA-MB-231 but only 3–5 days in others. IFN-γ plus S. aureus significantly amplified PD-L1, with up to a 2.9-fold increase in MDA-MB-468 and 1.5-fold in MDA-MB-231, but no effect in low-uptake lines. TLR2 agonists modestly increased PD-L1 in high-TLR2-expressing lines and synergized with IFN-γ. These effects were accompanied by STAT1 phosphorylation, supporting a TLR2/STAT1 axis linking bacterial sensing to immune checkpoint regulation. Conclusions: Together, these findings identify S. aureus as a modulator of immune signaling in TNBC and highlight the potential for microbial factors to influence ICI responsiveness. Targeting tumor–bacteria interactions may represent a novel strategy to enhance immunotherapy efficacy in breast cancer.

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and high resistance to chemotherapy. Doxorubicin is commonly used, but its efficacy is limited by variable sensitivity and resistance. Bacopaside II, a saponin compound, has shown anti-cancer potential. This study evaluates the effects of doxorubicin and bacopaside II, both individually and in combination, across TNBC subtypes to explore mechanisms of resistance and enhanced drug efficacy. Methods: The growth-inhibitory effects of doxorubicin and bacopaside II were assessed in four TNBC cell lines. IC50 values were determined using dose–response assays, and doxorubicin accumulation was measured via spectral flow cytometry. ATP-binding cassette (ABC) transporter expression (ABCB1, ABCC1, ABCC3, and ABCG2) was analyzed for correlations with drug sensitivity. In silico docking assessed the binding affinity of bacopaside II to ABC transporters. A 3D culture model simulated drug-resistant TNBC, and combination effects were evaluated with live-cell imaging. Results: Doxorubicin sensitivity varied across TNBC molecular subtypes, correlating to intracellular accumulation. Bacopaside II inhibited growth across subtypes, inducing apoptosis in sensitive cells and necrosis in resistant cells. Bacopaside II increased doxorubicin accumulation, independent of P-glycoprotein (ABCB1), possibly through interactions with other ABC transporters. In drug-resistant 3D cultures, bacopaside II maintained efficacy and enhanced doxorubicin accumulation, counteracting ABC transporter-mediated resistance. The doxorubicin and bacopaside II combination showed synergistic growth inhibition. Conclusions: Bacopaside II enhances doxorubicin efficacy in TNBC by increasing drug accumulation and overcoming ABC transporter-mediated resistance, suggesting its potential as an adjuvant in TNBC treatment. These findings support further investigation of bacopaside II, particularly for resistant TNBC subtypes.

The oral microbiome, studied by sampling the saliva or by oral rinse, has been long thought to have diagnostic capacity for head and neck cancers (HNC). However, previous reports on the HNC oral microbiome provide inconsistent results. The aim of this study is to consolidate these datasets and determine the oral microbial composition between HNC patients to healthy and premalignant individuals. We analyzed 16 published head and neck cancer (HNC) short-read 16S rRNA sequencing datasets, specifically targeting the V3V4, V4 and V4V5 regions. These datasets included saliva and oral rinse samples from donors with HNC, as well as from healthy and premalignant donors. Differences in diversities and microbial abundance were determined. HNC saliva displayed lower alpha diversity than healthy donors. In contrast, the opposite trend was observed for oral rinse samples. Beta diversity scores were largely similar across different patient types. Similar oral phyla were detected for all samples, but proportions were largely dependent on sample type (i.e., saliva or oral rinse) and primer set utilized for 16S rRNA sequencing. Neisseria, Leptotrichia and Megasphaera were elevated in healthy saliva, while Mycoplasma was elevated in HNC saliva. Oral rinse and saliva displayed similar enrichment for Fusobacterium, while Veillonella, Alloprevotella, and Campylobacter showed conflicting results. The sparse partial least squares discriminant analysis model performed effectively in discriminating HNC from healthy or premalignant patients using V3V4 saliva (AUC = 0.888) and V3V4 oral rinse (AUC = 0.928), while poor discriminative capacity was observed for V4 saliva (AUC = 0.688). In conclusion, our meta-analysis highlighted the limitations of 16S rRNA sequencing, particularly due to variations across study batches, primer sets (i.e., V3V4, V4), and sample types. Hence, caution should be exercised when interpreting 16S rRNA sequencing results across studies, especially when different primer sets and sample types are used.