Long noncoding RNA expression in the cervix mid-pregnancy is associated with the length of gestation at delivery

Figures & data

Table 1. Study participant characteristics (n = 78*).

Characteristic	Mean	SD
Age at enrollment (years)	32.9	5.8
Pre-pregnancy body mass index (kg/m^2)	25.1	4.7
Gestational age at cervical sampling^	15.5	5.0
Gestational age at birth^‡	39.0	0.2
	n	%
Maternal race/ethnicity
Non-Hispanic black	12	15.4
Non-Hispanic white	43	55.1
Hispanic	8	10.3
Asian	8	10.3
Other/multiple races/unknown	7	9.0
Nulliparous	35	44.9
Multiple gestations	6	7.7
Married	52	66.7
Income ≥ $75,000 per year	46	63.0
Education
Less than college	18	24.0
College degree	28	37.3
Graduate degree	29	38.7
Smoked prior to pregnancy	19	29.2
Preterm (< 37 weeks of gestation)	7	9.0

*Missing data: income n = 5, education n = 3, and smoking n = 13

^Range 8–26 weeks; ^‡Range 34–42 weeks

Table 2. Long noncoding RNAs (lncRNAs) detected in cervical samples from 78 pregnant women.

lncRNA	Descriptive name	Chromosomal location	Detected, n	Mean Ct	SD	Mean ΔCt*	SD
NEAT1	Nuclear parapspeckle assembly transcript 1	11q13.1	78	27.2	2.0	−0.6	1.0
TUG1	Taurine upregulated 1	22q12.2	70	32.6	1.2	5.2	1.2
ZFAS1	ZNFX1 antisense RNA 1	20q13.13	62	32.7	1.1	5.6	0.9
SRA1	Steroid receptor RNA activator 1	5q31.3	59	32.7	1.3	5.5	0.2
XIST	X inactive specific transcript	Xq13.2	52	33.4	0.9	6.5	1.2
TINCR	Tissue differentiation-inducing non-protein encoding RNA	19p13.3	48	32.6	1.2	5.4	1.3
MALAT1	Metastasis associated lung adenocarcinoma transcript 1	11q13.1	43	33.8	0.7	7.0	0.8
FALEC	Focally amplified long noncoding RNA in epithelial cancer	1q21.2	40	33.4	1.2	6.2	1.4
UCA1	Urothelial cancer associated 1	19p13.12	40	34.0	0.6	6.9	1.3

ΔCt, difference in cycle threshold for PCR amplification from housekeeping gene expression, higher ΔCt values represent lower levels of expression

*Normalized to 4 housekeeping genes (ACTB, B2M, RPLP0, and RN7SK)

Table 3. Associations of long noncoding RNAs (lncRNAs) from cervical samples obtained prior to 28 weeks of gestation and subsequent length of gestation at delivery.

	Difference in length of gestation in days (β (95% CI)) per doubling of lncRNA expression (-ΔCt)
lncRNA (Preterm/total, 7/78)	Unadjusted	Race/ethnicity adjusted
NEAT1 (7/78)	−0.64 (−3.3, 2.0)	−0.58 (−3.3, 2.2)
TUG1 (7/70)	−2.8 (−5.1, −0.46)	−2.8 (−5.2, −0.31)
ZFAS1 (7/62)	1.9 (−1.5, 5.3)	1.8 (−1.8, 5.4)
SRA1 (4/59)	1.3 (−1.1, 3.7)	1.7 (−0.94, 4.3)
XIST (6/52)	0.02 (−2.9, 2.9)	0.18 (−3.0, 3.4)
TINCR (5/48)	−2.4 (−5.1, 0.22)	−3.3 (−6.3, −0.22)
MALAT1 (4/43)	−0.97 (−5.7, 3.7)	−0.65 (−5.7, 4.4)
FALEC (5/40)	−4.7 (−7.3, −2.0)	−4.5 (−7.3, −1.6)
UCA1 (3/40)	−0.59 (−3.7, 2.5)	−1.2 (−4.6, 2.2)

Ct, cycle threshold; ΔCt, difference in lncRNA Ct value and housekeeping genes

Bold face signifies P < 0.05, only the model for FALEC remained significant at Bonferroni P < 0.0056.

Figure 1. Scatter plots of long noncoding RNA expression (-ΔCt values on x-axis; less negative values indicate higher expression) and gestational age at delivery.