Objective To analyse the single-nucleotide polymorphisms (SNPs): ABCB1 _1236C>T, ABCB1 _2677G>T/A, ABCB1 _3435C>T and haplotypes in the ABCB1/MDR1 gene, which could contribute to genetic risk of colorectal cancer (CRC). Disease association between the ABCB1/MDR1 genotype, allele, haplotype frequencies and histological features, such as TNM classification, localization of primary carcinoma, grade of malignancy, histological type of tumour, lymphoid infiltration and vessel invasion were estimated. In this study, the potential role of SNPs of the ABCB1/MDR1 gene as a prognostic marker for CRC was analysed. Materials and methods Tumour specimens of 95 patients with CRC were studied. Using automated sequencing or PCR-RFLP method, DNA for three common SNPs of ABCB1/MDR1 was extracted and analysed. The results of genotyping and haplotype analysis with histopathological features, grading and clinical staging of neoplasms were correlated. Results A statistically significant higher frequency of T₁₂₃₆ allele in T1/T2 (89.7%), M0 groups (81.6%) and I/II clinical staging (82.7%) in comparison with T3/T4 (68.2%), M1 groups (47.4%) and III/IV clinical staging (65.1%) was detected. Furthermore, multivariate analysis according to Cox's proportional hazard model indicated that the T₁₂₃₆ allele is a good, independent prognostic factor and the presence of this allele decreases the risk of death in comparison with a group without this allele (HR = 0.26; p = 0.0424). In addition, a statistically significant higher frequency of C₃₄₃₅ allele and significant differences in the C₃₄₃₅ allele distribution in N1/N2 group (91.7% and 62.5%, respectively) than N0 group (71.2% and 44.9%, respectively) was found. Each of the eight possible haplotypes was noted in M0 or I/II group and only seven in M1 or III/IV group. Haplotype T₁₂₃₆-G₂₆₇₇-C₃₄₃₅ only in less advanced CRC subjects (9.6% in I/II and 9.2% in M0 group) was detected. In addition, significant differences in haplotype distributions between M0 or I/II and M1 or III/IV group were found (p = 0.01 and p = 0.05, respectively). Conclusions These results suggest association between T₁₂₃₆ allele and T₁₂₃₆-G₂₆₇₇-C₃₄₃₅ haplotype and less advanced CRC, so these genetic markers may play a role as potentially good prognostic factors. Differences in haplotype distributions and degree of clinical staging may suggest that some other potential SNPs, especially in regulatory region of ABCB1/MDR1 gene, may influence P-glycoprotein function and CRC progression.

The ABCB1 gene belongs to ATP binding cassette (ABC) transporter genes that has been previously implicated in cancer progression and drug response. This study aimed to evaluate the association between the SNP 3435 and the expression of the ABCB1 gene in lung cancer patients in the Polish population in comparison to clinicopathological parameters and treatment. 150 RNA and 47 DNA samples were isolated from 49 lung cancer cases including both tissue samples and blood taken from the same patients at three time points: diagnosis, 100 days and one year after the surgical intervention. Qualitative and real-time PCR analysis of expression were done, also genotyping by PCR-RFLP. Mutant homozygous TT and allele T are present statistically significantly more frequently in the group of patients with lung cancer. There is no difference with expression level in lung cancer tissue and blood sample taken from the same patients before surgical treatment. On the basis of blood samples analysis it was observed that the expression level of ABCB1 mRNA was growing in time. Higher levels were marked after 100 days and one year after the surgical intervention. The complementary pharmacological treatment induced higher expression levels of ABCB1. The presented data suggest an important role of ABCB1 in lung cancer, the increasing level of ABCB1 mRNA which can be connected with induction of multidrug resistance mechanism is also significant, that observation must be confirmed in further analysis.

Panax quinquefolium hairy root cultures synthesize triterpenoid saponins named ginsenosides, that have multidirectional pharmacological activity. The first rate-limiting enzyme in the process of their biosynthesis is 3-hydroxy-3-methylglutaryl CoA reductase (HMGR). In this study, a 741 bp fragment of the P. quinquefolium HMGR gene (PqHMGR), consisting of a proximal promoter, 5′UTR (5′ untranslated region) and 5′CDS (coding DNA sequence) was isolated. In silico analysis of an isolated fragment indicated a lack of tandem repeats, miRNA binding sites, and CpG/CpNpG elements. However, the proximal promoter contained potential cis-elements involved in the response to light, salicylic, and abscisic acid (ABA) that was represented by the motif ABRE (TACGTG). The functional significance of ABA on P. quinquefolium HMGR gene expression was evaluated, carrying out quantitative RT-PCR experiments at different ABA concentrations (0.1, 0.25, 0.5, and 1 mg·L⁻¹). Additionally, the effect of abscisic acid and its time exposure on biomass and ginsenoside level in Panax quinquefolium hairy root was examined. The saponin content was determined using HPLC. The 28 day elicitation period with 1 mg·L⁻¹ ABA was the most efficient for Rg2 and Re (17.38 and 1.83 times increase, respectively) accumulation; however, the protopanaxadiol derivative content decreased in these conditions.